A new Hamas-led militia battled gunmen from a Fatah-dominated security force near the Palestinian parliament in Gaza on Monday in fresh internal fighting and medics said a Jordanian citizen was killed.

Palestinian security sources said the Jordanian was driving a car with Jordanian diplomatic licence plates when he was caught in crossfire. Six civilian bystanders and a policeman were wounded, medics said.

Witnesses said members of the new force set up by the ruling militant Islamic group returned fire after coming under attack.

Hamas officials said the assailants were from the Preventive Security agency, staffed largely by men loyal to the long-dominant Fatah group of President Mahmoud Abbas.

The Hamas security men took cover inside a building near parliament. Ordinary police also joined the battle, witnesses said. A vehicle belonging to Preventive Security was set on fire in the area, witnesses said. Civilians fled the streets.

Palestinian security sources said the Jordanian was an administrative employee at his country's mission in Gaza and not a diplomat.

Hamas, which took power in March after winning January elections, deployed its new 3 000-strong force in Gaza last week, prompting Abbas, a moderate, to order police onto the streets too. The rival forces clashed within barely a day.

Apparent assassination attempts against two top Abbas commanders at the weekend - one was badly wounded - have also stoked worries of further strife. Hamas has denied any responsibility for the two attacks.

Unidentified gunmen killed a militant from Fatah movement overnight in Gaza. Fatah accused Hamas of killing the man. Hamas said the gunman was killed when he and another man tried to kidnap a Hamas member in the southern Gaza strip.

Low-level skirmishes between the rival parties have fuelled fears of a civil war among Palestinian groups, which include not only Hamas and Fatah, but breakaway factions of both movements as well as the staunchly militant group Islamic Jihad.

Hamas, which is formally committed to Israel's destruction, has largely abided by a truce in attacks on Israelis for the past 15 months. But it has bolstered its forces in its Gaza Strip stronghold as it attempts to face down internal rivals.

Abbas's Fatah seeks a two-state solution to end the conflict.