JENIN, West Bank, (Reuters) – Fatah gunmen shot at the convoy of a minister from the rival Hamas movement in the occupied West Bank on Saturday, the first factional violence since Palestinian unity talks began a month ago.

Officials from both sides said Wasfi Kibha, minister of prisoner affairs, was unharmed in the shooting near Tubas, a town near the West Bank’s largest city of Nablus.

The incident sparked a gun battle in the area between Hamas and Fatah members in which one person was lightly wounded, Hamas sources said.

Fatah, headed by President Mahmoud Abbas, and officials from the ruling Hamas faction offered different accounts of the incident which occurred despite predictions by Hamas members that a joint government deal with Fatah was near.

Kibha told Reuters that Fatah gunmen had stopped his car at a makeshift checkpoint outside Tubas. “Without warning they shot at my car,” he said. His convoy turned around and headed in the opposite direction, towards the West Bank town of Jenin.

A Fatah official said their gunmen had opened fire only after armed members of a Hamas-led police force accompanying the minister’s car had shot towards them. A Palestinian photographer was injured by a bullet fragment in the head, the official said.

Hamas denies it has any police in the West Bank. Fatah has accused Hamas of seeking to build such a force there.

Disagreement over the Hamas police force in Gaza is a major obstacle to the sides wrapping up talks over a unity government.

After Saudi mediation, Hamas and Fatah agreed a month ago to forge a joint coalition cabinet, largely ending weeks of bloody factional fighting centred in the Gaza Strip in which more than 90 people were killed.

Abbas said on Thursday a unity deal was “99 percent” agreed although he had not yet agreed with Prime Minister Ismail Haniyeh of Hamas who would be interior minister, a post that controls the powerful security services.

Saeed Seyam, the current interior minister from Hamas, said the movement has demanded its police force remain intact under any unity deal, pending a reorganisation of the other security forces now dominated by Abbas’s Fatah. “The executive force will remain until the other security services are restructured,” Seyam said in Gaza.