How Hamas build force, plan surprise attack on Israel on 7 October

Five armed Palestinian groups bin join Hamas for di deadly 7 October attack on Israel, afta dem train togeda for one military-style exercise from 2020 until di attack, BBC News analysis show.

Di groups bin carry out joint drills for Gaza wey closely resemble di tactics dem use during di deadly assault – for one site wey dey less dan 1km (0.6 miles) from di barrier wit Israel – come post dem on social media.

Dem practice how to take pipo hostage, raiding compounds plus how to crack Israel defences during these exercises, di last exercise dem do just 25 days before di attack.

BBC Arabic and BBC Verify bin gada all di evidences wey show how Hamas bring togeda Gaza factions to sharpen dia combat methods - and ultimately execute one raide inside Israel wey throw di region into war.

'A sign of unity'

On 29 December 2020, Hamas overall leader Ismail Haniyeh bin declare di first of four drills dem codename Strong Pillar as "strong message and sign of unity" between Gaza various armed factions.

As di most powerful of Gaza armed groups, Hamas na di major force for one coalition wey bring togeda 10 oda Palestinian factions for inside one war games-style exercise wey di "joint operation room" dey oversee.

Dem set up di structure for 2018 to coordinate Gaza armed factions under one central command.

Prior to 2018, Hamas bin don formally coordinate wit Palestinian Islamic Jihad (PIJ), Gaza second largest armed faction and - like Hamas – wey be proscribed terrorist organisation for UK and oda kontris.

Hamas don also fight alongside oda groups for previous conflicts, but di 2020 drill bin show more groups wey dey unified.

Hamas leader tok say di first drill bin reflect di "permanent readiness" of di armed factions.

Di 2020 exercise na di first of di four joint drills wey hold over three years, dem document each of dem inside polish videos dem post on public social media channels.

BBC don visually identify 10 groups, including PIJ, by dia distinctive headbands and emblems wey dem use train alongside Hamas during di Strong Pillar drills for video dem post on di messaging app Telegram.

Afta di 7 October attack, five of di groups bin post videos to wey show say dem take part for di assault. Three odas bin issue written statements on Telegram to claim say dem follow plan and carry out di attacks.

Di role of these groups don come into sharp focus as pressure dey on Hamas to find dozens of women and children wey believe say oda factions carry dem as captives from Israel go Gaza on 7 October.

Three groups - PIJ, di Mujahideen Brigades and Al-Nasser Salah al-Deen Brigades - claim say dem seize Israeli hostages, alongside Hamas, on dat day.

Dem tok say efforts to extend di temporary truce for Gaza bin lie on Hamas locating those hostages.

While these groups bin come from broad ideological spectrum wey range from hard-line Islamist to relatively secular, all of dem share willingness to use violence against Israel.

Hamas statements bin repeatedly stress di theme of unity between Gaza desperate armed groups. Di group suggest say dem be equal partners for di joint drills, as dem continue to play leading role for di plans to attack Israel.

Footage from di first drill show masked commanders for inside one bunker and e be like say dem dey conduct exercise, and e begin wit a volley of rocket fire.

E cut to heavily armed fighters wey gada for one mocked-up tank wey carry Israeli flag, dem detain one crew member, drag am away as a prisoner, plus dem raid buildings.

We know from videos and disturbing statements from witness say dem use both tactics to capture sojas and target civilians on 7 October, kill around 1,200 pipo and take about 240 hostages.

Telling di world

Dem hold di second Strong Pillar drill almost exactly one year later.

Ayman Nofal, one commander for di Izzedine al-Qassam Brigades - di official name for Hamas armed wing – bin tok say di aim of di exercise on 26 December 2021 na to "affirm di unity of di resistance factions".

E tok say di drills go "tell di enemy say di walls and engineering measures on di borders of Gaza no go protect dem".

Anoda Hamas statement tok say di "joint military manoeuvres" bin dey designed to "simulate di liberation of settlements near Gaza" – wey be how di group dey refer to Israeli communities.

Dem repeat di exercise on 28 December 2022, and publish to mark di events propaganda fotos of fighters wey dey practice clearing buildings and overrunning tanks for wetin appear to be a replica of a military base.

Israel Defense Forces (IDF) bin previously carry out air strikes to scata Hamas training activities. For April 2023, dem bomb di site dem use for di first Strong Pillar drill.

Weeks before di attacks, female surveillance sojas near di Gaza border bin reportedly warn of unusually high drone activity plus say Hamas dey train to take over observation posts wey look like dia positions.

But, according to reports for di Israeli media, dem say authorities ignore dem. One Brigadier General Amir Avivi, former IDF deputy commander for Gaza, tell BBC.

"Plenty intelligence bin dey say dem dey do dis training - afta all, di videos dey for public, and dis bin dey happun just hundreds of metres from di fence dem share (wit Israel)".

But e tok say while di military know about di drills, dem "no see wetin dem bin dey train for".

Di IDF tok say dem "eliminate" Nofal on 17 October 2023, di first senior Hamas military leader wey die during di conflict.

Hiding in plain sight

Hamas bin go great lengths to make sure say di drills bin dey realistic.

For 2022, fighters bin practice how to storm one fake Israeli military base wey dey just 2.6km (1.6 miles) from di Erez crossing, one route between Gaza and Israel wey di IDF dey control.

BBC Verify don pinpoint di site for di far north of Gaza, just 800m (0.5 miles) from di barrier, dem match geographic features dem see for di training footage to aerial images of di area. As of November 2023, di site bin still visible on Bing Maps.

Di training camp bin dey within 1.6km (1 mile) of one Israeli observation tower and one elevated observation box, elements for security barrier wey Israel don spend hundreds of millions of dollars to construct.

Dem dig di mock base on land several metres below ground level, so e no go dey immediately visible to any nearby Israeli patrols - but pipo for see di smoke wey dey comot from di explosions, and IDF dey known to use aerial surveillance.

Hamas bin use dis site to practise storming buildings, taking hostages at gunpoint and destroying security barriers.

BBC Verify don use publicly available information - including satellite imagery - to locate 14 training sites for nine different locations across Gaza.

Dem even train twice for one site wey dey less dan 1.6 km (1 mile) from di United Nations aid agency distribution centre, and wey dey visible for di background of one official video wey di agency publish for December 2022.

Land, sea and air

On 10 September 2023, di so-called joint committee room bin publish images on dia dedicated Telegram channel of men for military uniforms dey carry out surveillance of military installations along di Gaza barrier.

Two days later, dem stage di fourth Strong Pillar military exercise, and by 7 October, dem don rehearse all di tactics dem go deploy for di unprecedented attack.

Dem feem fighters wey dey ride for di same type of white Toyota pickup trucks wey pipo see dey roam through southern Israel di following month.

Di propaganda video show gunmen dey raid mock buildings and fire dummy targets inside, plus as dem dey train to storm one beach wit boat and underwater divers. Israel tok say dem bin fight Hamas boat wey wan land on dia shores on 7 October.

However, Hamas no publicise dia training wit motorcycles and paragliders as part of di Strong Pillar propaganda.

One training video wey Hamas post three days afta 7 October show as dem demolish fences and barriers to allow motorcycles pass through, one tactic dem use reach communities for southern Israel. We no identify similar earlier videos.

Footage of fighters using paragliding equipment was also not published until the 7 October attack was under way.

For inside one training video dem share on di day of di attack, e show as gunmen land for one mock kibbutz for one airstrip we locate to one site north of Rafah for southern Gaza.

BBC Verify establish say e dey recorded some time before 25 August 2022, and e dey stored for one computer file dem title Eagle Squadron, di name wey Hamas dey use for dia aerial division – wey suggest say di paragliders plan don dey in di works for ova a year.

Di element of surprise

Before 7 October, pipo reason say Hamas get about 30,000 fighters for di Gaza Strip, according to reports wey quote IDF commanders. Pipo also reason say Hamas fit gada support from several thousands of fighters from smaller groups.

Hamas na by far di most powerful of di Palestinian armed groups, even without di support of oda factions.

Di IDF bin previously estimate say 1,500 fighters join di 7 October raids. Di Times of Israel bin report earlier dis month, di IDF now believe say di number dey close to 3,000.

Whatever di true number be, e mean say na only small fraction of di total number of armed operatives for Gaza take part for di attack. E no dey possible to verify di exact numbers of how many fighters from smaller groups join for di attack or di Strong Pillar drills.

While Hamas dey build cross-faction support for di build-up to di attack, Hisham Jaber, one former Brigadier General for di Lebanese army who be security analyst for di Middle East Centre for Studies and Research now, tok say im believe say na only Hamas dey aware of di ultimate plan.

Andreas Krieg, one senior lecturer in security studies for Kings College London, tell BBC say: "While centralised planning dey ground, execution dey de-centralised, wit each squad operationalising di plan as dem see fit."

Hugh Lovatt, one Middle East analyst for di European Council on Foreign Relations, tok say Israel fit don know of di joint training drills but "make dem reach wrong conclusion", e possible say dem assess am as "standard" activity of paramilitary groups for di Palestinian territories, instead of "make dem see am as bih kasala wey wan burst".

Israel Defense Forces for dia reaction for the issues wey dey raised for dis article, tok say "currently dem dey focus on eliminating di threat from di terrorist organisation Hamas" and questions about any potential failures "go dey looked into in a later stage".

E fit be several years until Israel formally understand whether dem miss opportunities to prevent di 7 October massacre.

Di ramifications for dia military, intelligence services and government fit be seismic.