UN deaths put pressure on Rome talks for ceasefire

BEIRUT (Reuters) - Israel's killing of four U.N. observers piled pressure on an international conference in Rome on Wednesday to end a 15-day-old Middle East conflict, as Hizbollah vowed not to accept any "humiliating" truce terms.

United Nations Secretary General Kofi Annan demanded Israel investigate the "apparently deliberate targeting" of a U.N. post in southern Lebanon where an Israeli air strike killed the four U.N. military observers on Tuesday.

Israel, waging a military offensive in Lebanon against Hizbollah guerrillas, announced it would hold a probe and expressed regret at the deaths but said it was shocked Annan had suggested the observers may have been deliberately targeted.

A Chinese national was among the four observers killed, China's official Xinhua news agency reported. It said the other three were from Finland, Austria and Canada.

U.N. officials said the air strike had caused the building housing the observers to collapse and that rescue teams had been sent to retrieve the bodies from the rubble.

"(This) attack on a long established and clearly marked U.N. post at Khiam occurred despite personal assurances given to me by (Israeli) Prime Minister Ehud Olmert that U.N. positions would be spared Israeli fire," Annan said in a statement.