Lebanese hold a candlelit vigil in memory of at least 56 people - more than half of then children - who were killed Sunday in an Israeli airstrike that crushed a building in the southern Lebanese village of Qana

Diplomatic efforts to end the fighting between Israel and Hezbollah militants were derailed Sunday after an Israeli airstrike on the southern Lebanese village of Qana killed at least 56 people, mostly women and children. In New York, U.N. Secretary General Koffi Annan urged the Security Council to condemn the attack and call for an immediate ceasefire, while Secretary of State Condoleezza Rice, who is in the Middle East, had to cancel her planned trip to Lebanon.

Secretary Rice had planned to meet with Lebanese leaders in Beirut, and expectations were she would leave the region with some concrete proposals for ending the more than two weeks of fighting.

The Israeli airstrike on the village of Qana set back those plans.

A visibly angry Lebanese Prime Minister, Fouad Siniora said this was not the time for negotiations. "There is no place on this sad morning for any discussions other than an immediate and unconditional cease-fire," he said.

U.N. Secretary-General Kofi Annan addresses the media during an emergency session of the Security Council

Later, at an emergency session of the U.N. Security Council in New York, Secretary-General Koffi Annan urged the Council to condemn the attack on Qana and call for an immediate cease-fire. "I am deeply dismayed that my earlier calls for an immediate cessation of hostilities were not heeded with the result that innocent life continues to be taken and innocent civilians continue to suffer," he said. "I repeat that call once again from this council chamber and I appeal to the council to do likewise."

The United States and Israel have resisted international pressure for an immediate truce, insisting that any halt to hostilities must be sustainable and long-term.

That position apparently remains. But in Jerusalem, Rice spoke of a cease-fire as "soon as possible." "I would have wanted one (cease-fire) yesterday, if possible, but the parties have to agree to a cease-fire and there have to be certain conditions in place. Any ceasafire has to have circumstances that are going to be acceptable to the parties," she said.

Rice said she was "deeply saddened" by the events in Qana and said all sides were pushing for an "urgent end" to the conflict.

The White House issued a statement expressing its condolences for the losses in Qana and said it continues to urge Israel to exercise the utmost care to avoid civilian life.

Israel says it does not target civilians. Speaking at the United Nations, Israeli Ambassador Dan Gillerman said those killed in Qana were the victims of Hezbollah actions. "While we mourn the deaths of those people, we must stress that Israel has never, and did not on this particular case, target innocent people. Kafr Qana has been for a long time a hub for Hezbollah. The Hezbollah has been launching missiles and rockets at Israel from Kafr Qana," he said.

While Israeli Prime Minister Ehud Olmert expressed "deep sorrow" over the Qana bombing, he vowed the fight against Hezbollah would continue.

Israel wants to diminish Hezbollah's capabilities and drive the militia back from the border so it can no longer threaten Israel.

It also wants Hezbollah to return the two Israeli soldiers militants captured July 12 and, in the longer-term it wants to see the group disarmed. Israel and the State Department each consider Hezbollah a terrorist organization.

Israeli officials indicated Mr. Olmert told Rice that Israel needs about two more weeks to continue its military campaign.

The attack on Qana has outraged Lebanese. Several-thousand people gathered in downtown Beirut to show their anger and ransacked a U.N. building.

Hezbollah has vowed revenge for the Qana attack.

Secretary-General Annan said it was Hezbollah's unprovoked cross border raid into Israel July 12 that ignited the current hostilities, but he said Israel's response is causing death and suffering on an "unacceptable scale."

And, Annan reminded both sides that the U.N. Human Rights Commissioner has cautioned they could be held accountable for "any breaches of international humanitarian law.