Tel Aviv - The Israeli security cabinet was expected to vote Saturday night on a ceasefire proposal, as the military campaign entered its fourth week and airstrikes continued overnight across the Gaza Strip.

The warplanes hit about 50 targets during the night, including rocket launching sites, tunnels under the Gaza-Egypt border as well as mosques used as points from where militants fired at Israel, a military spokesman said.

Israeli Prime Minister Ehud Olmert's office on Friday said there had been "significant progress" in talks in Cairo, where an Israeli delegation had been in discussions with Egypt's intelligence chief.

Israel and Hamas, the Islamist group which rules Gaza, do not talk to each other directly but go through Cairo, which has been pushing for a ceasefire based on a short-term "humanitarian" truce, followed by negotiations on a longer-term ceasefire that would include the Israeli security concerns and the militants' demand that the borders be opened.

The security cabinet vote would likely take place in the evening, after the end of the Jewish Sabbath, also giving Olmert and Defense Minister Ehud Barak time to discuss the proposal with their representatives who returned from two trips to Cairo in two days.

There has been speculation that Israel might surprise and go for a unilateral cessation of hostilities, a move United Nations Secretary General Ban Ki-moon had called for.

Israeli Foreign Minister Tzipi Livni signed a bilateral deal with US Secretary of State Condoleezza Rice in Washington on Friday, aimed at helping to curb arms smuggling into Gaza, as part of an effort to secure a ceasefire between Israel and Hamas militants.

Livni called it a "historic" deal that was a "vital component for the cessation of hostilities."

Khaled Meshaal, Hamas' Damascus-based political leader, said in Doha, at a summit of Arab leaders, that his organization would not accept Israeli dictates on the ceasefire, and that the militant group "had not suffered a defeat," in the Gaza fighting.

Some 1,192 Palestinians have been killed and over 5,100 injured since Israel began Operation Cast Lead on December 27, in an attempt to stop Palestinian rocket fire at southern parts of the Jewish state. The first week focussed on airpower and on January 3 the ground troops moved into the enclave.

Three Israeli civilians and 10 soldiers have died since the operation began, and over 700 rockets have been fired from Gaza. (dpa)