A Palestinian man and his son walk past a wall with three rockets painted on it in Jabalia, in the northern Gaza Strip, on Friday. (Mohammed Abed/AFP/Getty Images)

The UN agency responsible for giving food and other supplies to Palestinians in Gaza has stopped importing shipments into the area, complaining that the Hamas government is stealing aid meant for civilians.

The United Nations Relief and Works Agency (UNRWA) said Friday the Hamas government had taken "hundreds of tons" of food aid.

The agency's statement said 10 truckloads of flour and rice that had been delivered into Gaza on Thursday were taken away by trucks contracted by the Hamas-run Ministry of Social Affairs.

Earlier this week, Hamas police took thousands of blankets and food parcels bound for residents, the agency said.

"UNRWA’s suspension of imports will remain in effect until the aid is returned and the agency is given credible assurances from the Hamas government in Gaza that there will be no repeat of these thefts," the statement said.

Hamas did not immediately comment on the UNRWA statement.

Supplies running low

A spokesman for UNRWA said that although the agency will stop imports into Gaza, it will continue to distribute supplies already in the strip. But he cautioned that supplies are running low.

"There is enough aid for days, not weeks," Chris Gunness told the Associated Press.

Some 80 per cent of Gaza's 1.4 million people rely on the UN agency for food and other support, and UN officials say the need for aid has increased since Israel ended a military offensive in Gaza last month.

The offensive, an attempt to deter Hamas rocket attacks on southern Israel, killed nearly 1,300 people and caused widespread destruction.

Gaza's Hamas government followed with an announcement that it would hold its fire. But there has been sporadic fighting on both sides since.

Rockets fired into Israel

Also Friday, militants from the Gaza Strip fired two rockets into southern Israel, the Israeli army said.

The rockets landed near a communal farm, the military said. There were no reported casualties or damage as a result. An army spokesman said the rockets came from the northern Gaza Strip.

The rocket fire could threaten an already shaky ceasefire, an Israeli government spokesman suggested.

"It appears Hamas is deliberately undermining any chance whatsoever that calm will prevail in the south. They are playing with fire," Mark Regev, a spokesman for Israeli Prime Minister Ehud Olmert, told Reuters news agency.

About 40 rocket and mortar rounds have been fired at Israel since the Jewish state put an end to its offensive. While Israel holds Hamas responsible for all attacks from Gaza, it has conceded that more recent attacks may be the result of actions by smaller militant groups.

Friday's rocket fire followed an incident late Thursday on the Gaza-Israel border in which Israeli forces shot and killed a Palestinian who the military said was armed with a grenade.

Israeli vote looms

The attacks come just four days before Israelis vote in elections to replace Olmert's government. Recent polls indicate a two-way race between former prime minister Benjamin Netanyahu and Foreign Minister Tzipi Livni, with Netanyahu holding a slight edge.

One poll published Friday also suggests that Defence Minister Ehud Barak's Labour party has lost its third-place footing to the Yisrael Beiteinu party headed by Avigdor Lieberman.

The controversial Beiteinu party includes in its platform a policy to redraw Israel's borders in a way that would push areas with large Arab concentrations outside the country into Palestinian jurisdictions.

Lieberman also favours making citizens take an oath of loyalty to Israel. Those who refuse to take the oath would be barred from voting or running for office.

Lieberman was Netanyahu's chief of staff when the latter was prime minister. Some analysts have said Lieberman may be siphoning support away from Netanyahu.

Netanyahu has vowed to topple Hamas — which he calls an Iranian proxy — if he is elected.

With files from the Associated Press