The ruling Hamas faction accused forces loyal to Palestinian President Mahmoud Abbas of Fatah of trying to kill Prime Minister Ismail Haniyeh and vowed to punish those responsible, raising fears of civil war.
Hamas spokesman Ismail Rudwan singled out by name a top Fatah official and lawmaker -- Mohammed Dahlan -- as being behind the shooting attack on Thursday on Haniyeh's convoy outside the Rafah border crossing between Gaza and Egypt.
One of Haniyeh's bodyguards was killed. Another bodyguard, the prime minister's son and a political adviser were wounded.
"Mohammed Dahlan bears the direct responsibility for the assassination attempt which targeted the prime minister and he bears responsibility for the blood of the martyrs in the incident," Rudwan told a news conference in Gaza.
"The dirty hands which assassinated and wounded the body guards of the prime minister and attacked the prime minister's convoy will not escape punishment," he added.
Rudwan offered no evidence of Dahlan's involvement.
Dahlan was not immediately available to comment.
Tawfiq Abu Khoussa, Fatah's spokesman in Gaza and the West Bank, rejected Hamas's accusations.
"Fatah has condemned the incident and is demanding the formation of an official investigation committee," he said.
Rudwan called on Abbas to remove his presidential guard from the streets of the Gaza Strip and from the Rafah crossing.