By Tom Perry
BEIRUT (Reuters) - Lebanese protesters broke into the United Nations headquarters in Beirut on Sunday, smashing windows and ransacking offices, after an Israeli air strike killed at least 40 people in south Lebanon.
Several thousand people massed outside the building in downtown Beirut chanting "Death to Israel, death to America. We sacrifice our blood and souls for Lebanon."
By early afternoon, most protesters had drifted away leaving a few hundred people milling in a car park opposite the building, which was being protected by a line of Lebanese soldiers.
Geir Petersen, the personal representative of U.N. Secretary General Kofi Annan in Lebanon, condemned the Israeli attack on the village of Qana and called for an immediate investigation.
"I strongly condemn today's killing of tens of civilians by Israeli shelling of residential buildings in the village of Qana," he said in a statement.
Petersen was not at the U.N. offices in Beirut when they were attacked.
U.N. spokesman Khaled Mansour said the building had been stoned and furniture smashed but no U.N. staff were hurt as they had taken refuge in the basement. He said a small fire was started on the second floor but it had been contained.
Demonstrators held aloft the flags of Lebanon, Hizbollah and the Amal party, whose leader, Parliament Speaker Nabih Berri, appealed for a halt to the attack.
"Give the world a chance to stand by us," he said on local television.
CALLS TO ATTACK TEL AVIV
Demonstrators tore down a United Nations flag outside the building and ripped it to shreds and called on Hizbollah leader Sayyed Hassan Nasrallah to launch rocket attacks on Tel Aviv.
"Oh Nasrallah, oh our cherished one, destroy, destroy Tel Aviv," they chanted.
Members of Hizbollah, the Shi'ite group that sparked the war 19 days ago when it seized two Israeli soldiers and killed eight in a cross-border raid, tried to restrain the crowd.
The protesters gathered after an Israeli attack early on Sunday killed at least 40 people, including 23 children, in the southern Lebanese village of Qana.
Following the attack, Lebanon canceled a planned visit by U.S. Secretary of State Condoleezza Rice on Sunday, saying she was unwelcome until a ceasefire was declared.
At least 523 Lebanese, mostly civilians, have been killed since the conflict started and there is growing anger in Lebanon that the international community has not done enough to stop it.
"It's tense, we understand the anger and the rage of the people outside because of the Israeli shelling, but we don't understand why the U.N. building and its staff, many of them Lebanese, are to blame," said Mansour, speaking from the basement of the UN building.