Lebanese Prime Minister Fouad Siniora called for emergency meeting of the UN Security Council to consider an immediate cease-fire after at least 51 Lebanese were killed in Israeli airstrike on the southern Lebanese village of Qana yesterday.

Siniora urged UN Secretary General Kofi Annan by telephone to convene an emergency meeting of the Security Council to arrange an immediate cease-fire, officials said.

At least 51 Lebanese, including 22 children, were killed in an Israeli air raid on the village of Qana Sunday morning when two missiles slammed into a four-story building where people were taking shelter.

Angry Lebanese crowd broke into the UN headquarters in Beirut to protest the raid on Qana, the deadliest single Israeli attack since the conflict began 19 days ago.

Siniora ruled out any talks on finding a durable end to the conflict until there was an immediate halt to Israel's offensive.

"There is no place on this sad morning for any talks other than an immediate and unconditional ceasefire as well as an international investigation into Israel's massacres in Lebanon now," Seniora told reporters after the Qana bombing.

Lebanese government cancelled a planned visit to Beirut by U.S. Secretary of State Condoleezza Rice on Sunday.

Rice, who returned to Israel on Saturday to press for a ceasefire deal, said that she was saddened by the bombing but refrained again from calling for an immediate truce in the war between Israel and Hezbollah.

"I think it is time to get to a ceasefire ... We actually have to try and put one in place," Rice said in Jerusalem Sunday.

Rice, however, reiterated that a ceasefire could not mean are turn to the position before the war, which was triggered by Hezbollah's abduction of two Israeli soldiers in a raid out of south Lebanon on July 12.

Israeli Prime Minister Ehud Olmert said on Sunday that Israel would not rush into a ceasefire until the goals were achieved.

The Israel Defense Forces (IDF) said it had warned residents of Qana to leave and said Hezbollah bore responsibility for using it to fire rockets at Israel.