A statement by UNRWA (United Nations Relief and Works Agency for Palestine Refugees) said the incident occurred after it delivered 370 tonnes of flour, oil, lentils, sugar, rice and whole milk to Bait Hanun in northern Gaza on Wednesday - food supplies meant for 20,000 civilians, or two-thirds of the besieged population.
An Israeli armoured personnel carrier opened fire at a five-vehicle convoy marked with UN flags and symbols, after UNRWA Commissioner-General Peter Hansen and operations personnel made the distributions, according to the statement.
There were no casualties, a UN official said.
Hansen and other UNRWA personnel took cover in a nearby family home. After contacting an Israeli liaison office and waiting for 30 minutes, the convoy was allowed to leave the area.
The UNRWA chief, who had coordinated the trip in advance with the Israelis, said the soldiers deliberately fired at the UN.
"They were clearly associated with our being there. I would
think they were warning shots or random shots," said Hansen.
Israeli military sources said they were not targeting the UN but Palestinian fighters. Witnesses said there were no resistance fighters in the area at the time.
Wednesday's shooting came days after witnesses said Israeli forces fired on a convoy of the International Committee of the Red Cross in Bait Hanun. No one was hurt in that incident.
Israel cut off the town from the rest of Gaza on 28 June and since then its residents have been living under what UNRWA describes as severe hardship.
Hansen (R) says Israeli troops
deliberately fired at UN convoy
"Fresh food supplies have been running low, breadwinners have been unable to reach work, and in areas water and electricity infrastructure have been destroyed by Israeli armour," the aid group said in a statement.
Israeli Defence Minister Shaul Mofaz has vowed that the incursion will continue until a planned Israeli unilateral withdrawal from Gaza by the end of 2005.
In March the UN was forced to temporarily suspend food distributions in Gaza because of Israeli restrictions imposed on containers and staff, affecting between 700,000 to 1.2 million civilians.
UN envoy 'unwelcome'
Meanwhile, the top UN envoy to the Middle East will no longer be welcome in the occupied Palestinian territories after he harshly criticised Palestinian President Yasir Arafat, a senior adviser to the Palestinian president said on Wednesday.
"Terje Roed-Larsen's statement is not objective. As of today he is an unwelcome person in Palestinian territories," Nabil Abu Rudainah, referring to remarks by the envoy at the United Nations on Tuesday.
Larsen accused Arafat of giving "only nominal and partial support" to Egyptian efforts to support Palestinian security reforms demanded by the international community in an effort to end the intifada and renew moribund peace talks.
Although Arafat remained confined to his West Bank headquarters under virtual house arrest, surrounded by Israeli occupation forces, "this is not an excuse for passivity and inaction", Larsen said.
Abu Rudainah called on UN Secretary-General Kofi Annan to "look into Larsen's behaviour" and suggested that he dispatch "neutral envoys".