Israeli forces have imposed a complete closure on the Palestinian territories until after Israel's general election on Tuesday.

Curfews and cordons will bar all Palestinians from entering Israel, confining most of them to their communities.

Ariel Sharon: Tipped to win on Tuesday

Defence Minister Shaul Mofaz said that within Israel itself, soldiers would be deployed alongside police during voting, because of a large number of warnings about possible attacks.

He was speaking just hours after the Israeli army carried out a raid deep into the Gaza Strip, in which 12 Palestinians were killed and more than 50 others wounded.

A senior Palestinian minister, Yasser Abed Rabbo, accused Mr Sharon of launching the operation as part of his election campaign.

"It's quite obvious that this is the election card with which Sharon intends to continue his election campaign," he said.

Fierce resistance

Saturday's incursion is believed to be the biggest into Gaza City since the Palestinian uprising began more than two years ago.

Palestinians put up fierce armed resistance as some 50 tanks and armoured vehicles backed by helicopter gunships entered the city, but the Israeli army says it suffered no casualties.

Gaza residents spent Sunday clearing up and burying their dead. About 40,000 Palestinians marched at a mass funeral, firing shots into the air.

Most of the Palestinian dead appear to be men in their twenties. The militant group Hamas has already vowed revenge.

Show of strength

Mr Sharon is running for re-election on a platform of no negotiations with the Palestinians, as militant attacks and tough military reprisals continue.

Medics struggled to cope with the casualties

Mr Sharon is currently predicted to defeat the new leader of the Labour Party, Amram Mitzna, who has pledged to withdraw from the Gaza Strip within a year.

Defence Minister Mofaz told Israel radio that the government in the past had considered simply taking over the Gaza Strip, and that this was still under consideration.

The BBC's Liz Blunt in Jerusalem says the Gaza incursion was a major show of strength which should go down well with voters.

But for Israel to put a permanent presence into Gaza would be a major and potentially very costly undertaking, she says.

Revenge

Mr Mofaz said the raid, which ended at daybreak, was aimed at sites where Palestinians made and launched rockets at Israel after a recent increase in such attacks.

Three of the 12 were killed by missiles, the rest from gunfire as clashes erupted between Israeli troops and gunmen.

The troops stormed several buildings, destroying at least three metal workshops, as mosques called on Palestinians to resist the incursion.

Palestinians responded with assault rifles, anti-tank missiles and explosives, the Israeli military said.

Correspondents say that the area is a known stronghold of the group Hamas, which does not recognise Israel's right to exist and has carried out dozens of attacks to pressure Mr Sharon's government into a complete withdrawal from the Palestinian territories.

Rocket attacks

It was the third successive night that the Israeli army had been in action in Gaza Strip.

Mr Mofaz said on Friday a series of operations would be launched to end rocket strikes from the region, which earlier in the week left three Israeli soldiers dead.

Despite the incursion, another Qassam rocket was reportedly fired from northern Gaza on Sunday.