Three Israeli soldiers have been killed by Palestinian gunmen near the West Bank city of Hebron.

The soldiers were ambushed at a junction near the Jewish settlement of Beit Haggai.

Two radical Palestinian groups - the armed wing of Hamas and the al-Aqsa Martyrs' Brigades, linked to Palestinian leader Yasser Arafat's Fatah faction - claimed responsibility for the attack.

Early on Friday, Israeli helicopter gunships were reported to have fired missiles at targets in Gaza City, injuring one person, according to local hopsital staff.

The flare-up in violence comes just five days before Israelis vote in the country's general elections, which right-wing Israeli Prime Minister Ariel Sharon seems certain to win.

Tense times

Tensions have been high in Hebron since November, when 12 Israeli security forces were killed in an ambush, prompting the army to take over the Palestinian-controlled section of the city.

Sharon looks set to be re-elected

On Friday, Palestinian militants shot and killed an Israeli settler in a house just outside Hebron.

Correspondents say past attacks have benefited hardliners in Israeli polls.

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

He 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.

Mr Sharon says Israel cannot give up Hebron, as the holy tomb of the Jewish forefathers Abraham, Isaac and Jacob is situated there.

Mr Mitzna favours withdrawal from Hebron and the large majority of settlements in the West Bank and Gaza Strip.

Militant's wife detained

In a separate incident, a Palestinian man was reportedly wounded by Israeli gunfire earlier during an incursion into the southern Gaza town of Rafah.

More than 10 Israeli tanks and a bulldozer entered the town, with troops opening fire on an unspecified target, Palestinian medical and security sources said.

Also on Thursday, Israeli forces detained the wife of the jailed leader of the radical Popular Front for the Liberation of Palestine (PFLP), as she tried to cross from the occupied West Bank to Jordan.

Israeli government officials refused to comment about the detention of 47-year-old Ablah Saadat, wife of Ahmad Saadat - who is held in Jericho under US-UK supervision at the request of Israel after the PFLP's assassination of an Israeli cabinet minister in 2001.

Mrs Saadat had been planning to fly from Jordan to Brazil to attend the World Social Forum which began Thursday, according to the Palestinian human rights group Palestine Monitor.