Palestinian gunmen shot and killed a Hamas-linked judge as he arrived for work in the Gaza Strip Wednesday, escalating the tension between rival factions Hamas and Fatah.

Palestinian security officials said the man killed was Bassam al-Fara, a judge at the Islamic court and a Hamas member who belongs to the largest clan in the southern town of Khan Younis. He was believed to be either 28 or 30 years old.

Witnesses said four gunmen forced al-Fara to his knees when he got out of a taxi and shot him on the sidewalk, which was riddled with bullet holes.

In a text message to reporters, Hamas blamed a Fatah "death squad" for the shooting, which came two days after three children of a Fatah-allied intelligence officer were killed.

"This is an ugly crime committed against one of the field commanders of Hamas' military wing and one of the prominent figures in Hamas,"  Hamas spokesperson Fauzi Barhoum said.

"Hamas is not going to forget the blood of its members. It is going to pursue and bring to justice those who were involved in today's crime."

A Fatah representative denied responsibility for the shooting, which took place outside the courthouse in the southern town of Khan Younis.

"We condemn all acts of anarchy, whatever may be behind them. We call on the brothers in Hamas to stop firing accusations before the investigation," said Fatah spokesman Tawfik Abu Khoussa.

PM cuts foreign visit short

About 1,000 Fatah supporters marched through Gaza, calling on President Mahmoud Abbas, a Fatah member, to end the violence.

Palestinian Prime Minister Ismail Haniyeh, a member of Hamas, said he would cut short a visit to Sudan and return to Gaza Thursday to "resolve the internal problems."

"We want to assure you that words such as 'civil war' don't exist in our dictionary. They don't exist in our makeup, in our culture," Haniyeh said. "We will protect the national unity of the Palestinian people and we will thwart any attempt to instigate an inter-Palestinian struggle."

The incident dims hopes for a unity government between Fatah and Hamas, which won a parliamentary election earlier this year.

Moderate President Mahmoud Abbas's Fatah party and the Islamic militant Hamas have been locked in a power struggle since Hamas ousted Fatah in parliamentary elections. More than 40 Gazans have died in battles between the two groups since Hamas took power in March.

With files from the Associated Press