Unidentified gunmen killed three sons of a Palestinian intelligence official loyal to President Mahmoud Abbas in Gaza yesterday, firing at the car as it dropped them at school, police and hospital officials said.

An adult bystander was also killed in the attack in Gaza City, amid growing tension between Hamas, the governing militant movement and Abbas's Fatah faction.

Angry mourners firing automatic weapons later stormed into the compound of parliament during a funeral procession for the boys, who were aged between 6 and 9. Witnesses said the mourners fired

at the building. It was unclear if anyone was hurt.

Some 2,000 people took part in the funeral march, including the boys' father, Colonel Baha Balousha, who was heavily guarded by gunmen. Relatives carried his three sons, whose bodies were wrapped in white sheets, intheirarms.

The car taking the children to school was peppered with bullet holes, and blood stains covered the seats. Two school bags, one green and theotherblue, still lay inside.

"Masked gunmen took off in a yellow car after they fired many bullets at the car. Children were screaming and weeping in fear," said a primary school boy who witnessed the attack.

Several other schools line the street, which was crowded with children at the time of the shooting.

Residents said the gunmen fled with Hamas policemen in pursuit. Hospital officials said the dead bystander was a 25-year-old man. Police said two other children were wounded.

Balousha, a senior intelligence official, was not in the car when it was attacked.

Unknown gunmen tried to kill Balousha when they ambushed his car in Gaza in September, one of several attacks on top intelligence officials loyal to Abbas in the strip this year.

A senior Palestinian intelligence official in the occupied West Bank condemned the latest attack.