The Islamic Hamas movement has vowed revenge after the Israeli military killed a militant in an targeted attack as violence spread into Lebanon.
The pledge of revenge came after the latest Israeli-Palestinian violence left four dead, including Hamas activist Mr Baker Hamdan, killed late last night when an Israeli helicopter fired a missile at his car.
The attack came only hours after former Christian militia leader Elie Hobeika, who was accused of directing massacres at Palestinian refugee camps during the 1982 Israeli invasion, was killed along with three bodyguards in a car bombing in a Beirut suburb.
Israel rejected accusations by Lebanese President Mr Emile Lahoud that Israeli Prime Minister Mr Ariel Sharon, who was defence minister at the time of the 1982 Sabra and Shatila massacres, was trying to erase traces of his involvement in the events.
Relatives of victims killed by the Lebanese Forces Christian militia, of which the slain Mr Hobeika was intelligence chief, are trying to sue Mr Sharon for war crimes in a Belgian court.
Mr Hobeika had said he was ready to testify in Belgium if the case came to court. A Belgian court is to rule in six weeks whether the case can go ahead.
The United Nations has voiced concern the violence was spreading even further, citing a border skirmish in southern Lebanon between Shiite Muslim Hezbollah guerrillas and the Israeli military on Wednesday.
The Israeli killing of Mr Hamdan, a Hamas activist and two other passengers was justified by an Israeli army spokesman who claimed he was the chief of Hamas's military wing and that he was linked to the killing of four Israeli soldiers on the edge of the southern Gaza Strip.
A Hamas official told AFP: "Hamas will not keep its arms crossed in the face of the assassination of one its members and the resistance will carry on until the liberation of Palestine".
Earlier, two Jewish settlements came under attack from Palestinian militant groups. The Popular Front for the Liberation of Palestine said two men killed in a blast near Kfar Darom were suicide bombers trying to attack the settlement.
In Ramallah, where Israeli tanks have taken over large parts of the town and surrounded Mr Yasser Arafat's West Bank headquarters, a member of the Palestinian security forces was shot dead in overnight gunfire.
AFP