Gaza City, Gaza Strip ? Assailants gunned down a Muslim preacher known for his anti-Hamas views Friday, witnesses said, moments after he exited a mosque where he delivered a sermon criticizing the Islamic group’s role in a wave of Palestinian violence.

The slaying came as thousands of mourners marched through Gaza City carrying the bodies of seven Fatah men killed in a standoff with Hamas. Thursday’s gunfight was the bloodiest single battle in weeks of factional fighting, and Fatah said it was suspending talks with Hamas until the assailants are brought to justice.

Palestinian Prime Minister Ismail Haniyeh of Hamas urged Palestinians to focus on fighting Israel.

“Our fight is not an internal one, it’s against the occupation,” Haniyeh said after Friday prayers in Gaza City, the Haaretz daily reported on its Web site.

There was no claim of responsibility for Friday’s shooting of Adel Nasar, a mosque preacher who was shot as he got into a car in the Mughazi refugee camp in central Gaza, according to witnesses.

But Fatah accused Hamas. “Sheik Nasar was killed after he came out of the mosque where he criticized Hamas after the crime committed by some of its gunmen yesterday,” the group said in a statement.

Salem Salama, a lawmaker and top Hamas official in central Gaza, denied any involvement by his group.

“Hamas condemns this cowardly assassination,” he said. “We will work with all the honorable people here to find the killers and bring them to justice.”

A Palestinian man examines damage to the home of Fatah-loyalist security force officer Col. Mohammed Ghayeb, who was attacked during factional fighting between forces loyal to Fatah and Hamas in the Jebaliya Refugee Camp in the northern Gaza Strip. Ghayeb, head of President Mahmoud Abbas' Preventive Security Service in northern Gaza, was killed when Hamas gunmen assaulted his home with homemade rockets and grenades Thursday.

Witnesses said Nasar’s assailants pulled up to him in a white car and sped away after the shooting.

Nasar, 50, was not openly affiliated with any political party, but he was a well-known figure in the refugee camp and often preached against Hamas. Shortly before the shooting, witnesses said Nasar had criticized Thursday’s deadly attack on the home of Col. Mohammed Ghayeb, a top Fatah official in northern Gaza.

In his sermon, Nasar warned that God would punish the killers of Ghayeb and his bodyguards. He also said God would punish Palestinian rulers for not preventing the attack, said Jibril Awwar, a friend of the preacher who was slightly wounded in Friday’s shooting.

Nasar did not mention Hamas by name, but Awwar said the preacher’s message was aimed at the group, which controls most of the Palestinian government.

Political tensions have been high since Hamas defeated Fatah in parliamentary elections a year ago. Palestinian President Mahmoud Abbas of Fatah favors peace talks with Israel. Hamas refuses to recognize Israel’s right to exist, despite international sanctions against its government.

The political tensions erupted into violence last month after three young sons of a Fatah security commander were killed in a drive-by shooting. In all, more than two dozen people have died in the infighting.

The violence prompted an urgent meeting early Friday between Abbas and Haniyeh. Though the two sides agreed to pull back their forces, the meeting failed to cool raging tensions.