Gaza/Tel Aviv  - Israel's air force continued pounding the Gaza Strip from the air Thursday, with its solders pressing on with attacks against militants on the ground.

Meanwhile, government officials who were in Cairo to discuss proposals for ending the fighting, which has lasted 13 days so far and claimed hundreds of fatalities, ended the talks without results, Egyptian foreign ministry officials said.

Even as the Cairo talks on the ceasefire were taking place, caretaker Israeli Prime Minister Ehud Olmert said the bottom line of the military campaign was to "change the reality" in southern Israel, meaning an end to militant rocket attacks from the enclave.

"To this we have not yet arrived, and the Israel Defense Force has not yet been asked to carry out everything necessary to do so," said Olmert while visiting the army's Gaza division headquarters.

Also Thursday, the United Nations Relief and Works Agency UNRWA said it had "suspended all movement of staff" in the Gaza Strip after a driver bringing humanitarian supplies into the enclave was killed when the aid convoy was fired upon. Later, another UN convoy with international staff came under fire.

The aid convoy had UN flags and the drivers were wearing UNRWA vests, the organization's spokesman Adnan Abu Hasna said, noting that details were still sketchy and that the agency was gathering more information.

Abu Hasna said the suspension of activity was to protest the attack and lack of access for aid workers in the enclave. However, it was also a safety measure.

The second incident occurred during a three-hour lull in the fighting designed to allow aid trucks into the enclave. The lull also gave residents a chance to stock up on basic supplies and medical teams an opportunity to reach the wounded and dead in areas which had seen heavy fighting and were inaccessible to the medics.

Earlier, in an unusual move, the International Committee of the Red Cross slammed Israel for not allowing medics to access the dead and wounded in certain areas of the Gaza Strip during a four-day period, thereby violating international law.

The organization said that during a lull Wednesday its rescue teams had uncovered over 16 wounded and 18 killed, all trapped under rubble. In one case, four emaciated children were found lying with their dead mothers.

An Israeli military spokesman said Palestinian militants fired at least four rockets at Israel between the pause, which lasted from 1 pm and 4 pm (1100 GMT to 1400 GMT).

The first humanitarian lull, on Wednesday, had passed without incident.

In the actual fighting, Israel had carried out approximately 24 air attacks on targets in the Strip by mid-afternoon Thursday, an Israeli military spokesman said. Militants launched at least 15 missiles at mortars at Israel.

In the Gaza Strip, medical official Mo'aweya Hassanein said 11 Palestinians were killed Thursday and 40 were wounded.

One Israeli officer was killed in the ground fighting, and another wounded, by an anti-tank rocket fired by militants in the Strip.

The latest deaths bring to 763 the number of Palestinians killed, and 3,120 the number of wounded, in the 13 days of fighting. During that time, seven Israeli soldiers and three civilians have been killed as a result of rocket attacks and in the ground battles.

Residents reported heavy shelling in the southern Gaza border town of Rafah overnight. An Israeli military spokesman said Israel bombed another 15 smuggling tunnels running under the border with Egypt, as well as what he said was the house of a militant commander who oversaw the rocket attacks from the Rafah area toward nearby Israeli targets.

Some 5,000 residents of Rafah fled to two UN schools turned into shelters after Israeli helicopters dropped leaflets warning them to leave their homes along the Gaza-Egypt border. The leaflets stated Hamas was using houses along the border to hide the entrances to tunnels used for weapons smuggling.

A guaranteed end to Hamas' arms supply is one of Israel's main conditions for ending the fighting.

Although an Israeli Defence Ministry spokeswoman would give no details of what defence ministry official Amos Gilad and Olmert's advisor Shalom Turjeman had discussed in Cairo, Israeli media reported they wanted to raise the possibility of a permanent American presence along the Gaza-Egypt border.

The Israeli government earlier on Wednesday said it viewed Egyptian-French attempts to reach a diplomatic solution to the Gaza crisis "positively." US Secretary of State Condoleezza Rice said Wednesday that the United States, which has rejected several others, supports the Egyptian initiative.

But Israel also threatened to expand its ground offensive if the diplomatic attempts failed, with the Israeli cabinet in a meeting Wednesday authorizing the continuation of the Gaza offensive. Thus far, the Israeli ground troops are stationed on the outskirts of Gaza City, the Jabaliya refugee camp in the north and Khan Younis in the south, but have avoided penetrating deep into populated areas. (dpa)