Two explosions ripped through a house near the office of Palestinian President Yasser Mr Arafat's Fatah faction in the West Bank city of Hebron today, killing at least one person, security officials said.
Palestinians and Israelis disputed the cause of the blast.
A senior Fatah official, Mr Abbas Zaki, said Israel fired ground-to-ground missiles at the house.
"It was their intention to bombard Fatah headquarters in Hebron but by mistake they hit a neighbouring house," said Mr Zaki.
A second Fatah official, Mr Theyab Al-Sharabati from Hebron, said rockets were fired towards the office minutes after a Fatah meeting had been scheduled to take place. The meeting had been cancelled due to security alert.
But a statement from Israeli Prime Minister Mr Ariel Sharon's office said the Israeli army and security forces did not carry out any kind of military attack against the Palestinian Authority tonight and any claim regarding such an activity is incorrect and liable to escalate the situation in the field .
An Israeli military source said the explosion may have been caused by a work accident, the result of preparing explosives.
Hospital officials identified the dead man as Mr Rajae' Abu Rajab (35), the owner of the house, and said at least three other people were wounded.
A Reuters cameraman at the scene saw Palestinian security officers trying to pull wounded people out from under rubble from the blast and ambulances rushed to the site, on a main street in the Palestinian-ruled part of the city.
The death was the latest in a Palestinian uprising against Israeli occupation in the West Bank and Gaza Strip which erupted in late September after peace talks stalled.