The dramatic operation in which British forces rescued the seven hostages held by the West Side Boys was complex, risky, and meticulously planned.

Up to 150 troops and five helicopters took part in the two-pronged assault, as dawn was breaking over the Sierra Leone jungle hideout.

The timing of the operation was crucial: There was just enough light for the helicopters to see where they were going, but they could not be easily spotted themselves.

Chinooks: Used to swoop on rebel base

Speed was also of the essence. The hostages were being guarded by about 50 men and women, who were ready to start shooting at first sight of a helicopter.

Three giant Chinook helicopters ferried 110 soldiers from the renowned Parachute Regiment into the two landing zones, while two smaller Lynx helicopters provided supporting fire.

Within 20 minutes, the hostages were in a helicopter, being whisked back to safety after their 16 day ordeal in captivity.

Two-pronged attack

The most daunting military problem facing planners was the fact that the West Side Boys had at least two encampments, separated by the 300 metre-wide Rokel Creek.

One position, to the south, was effectively able to provide covering fire for the other, to the north, where the hostages were being held.

Hostage crisis

25 August: 11 British soldiers captured with Sierra Leonean colleague 30 August: Militiamen free five British soldiers 31 August: Kidnappers issue political demands 6 September: Plan for military operation finalised 10 September: Remaining hostages freed

Both positions had to be attacked simultaneously. The northern camp, the West Side Boys' headquarters, was quickly overwhelmed.

But the southern position took much longer to secure. Fierce fighting continued for up to an hour and a half, with British troops even having to use mortars.

The militia group lost 25 dead and about 18 of their fighters were captured, including their commander.

One British soldier was killed in the attack, and another was seriously injured. Eleven more personnel received what are described as light injuries.

Massive operation

The Army, Navy and RAF were all used to overpower the rag-tag militia group, who were thought to number about 200, many of them women and children.

Children are widely used as soldiers

There has been unconfirmed speculation that the elite SAS troops were also used to provide information and take part in the attack.

Defence analyst Colonel Andrew Duncan said he believed special forces would have been "key", rescuing the hostages while other soldiers concentrated on distracting the West Side Boys.

It has been claimed that the West Side Boys are an ill-disciplined group, often high on drink and drugs, but they are also well-equipped and determined fighters

The BBC's Allan Little in Freetown, the capital of Sierra Leone, said the West Side Boys managed to retreat after the initial assault and then open fire on the rescuers from the edge of the jungle.

He said the operation continued into the late afternoon as British forces consolidated their position and then carefully withdrew troops and equipment.

Jungle experience

Paras have experience of Sierra Leone

The West Side Boys are also experienced jungle fighters, and were intimately familiar with the terrain, a mixture of jungle and mangrove swamps.

However, the Parachute Regiment soldiers who made up the bulk of the rescue force also have jungle experience.

They served in Sierra Leone for three weeks earlier this year and returned on Thursday after flying to Dakar in Senegal from the UK last week.