Updated

The United States on Sunday condemned attacks on embassies in Libya's capital, a day after officials said a NATO missile strike had killed one of the sons of Libyan leader Moammar Qaddafi.

"We have seen reports indicating that British, Italian and U.S. diplomatic facilities in Tripoli have been attacked," U.S. State Department spokesman Mark Toner said. "If true, we condemn these attacks in the strongest possible terms."

Toner added: "The Vienna Convention requires that the Qaddafi regime protect diplomatic missions in Tripoli. By failing to do so that regime has once again breached its international responsibilities and obligations."

After news of Saturday's air strike spread in Tripoli, angry mobs trashed the embassies of Britain and Italy, a U.S. consular department and a United Nations office, said Libyan Deputy Foreign Minister Khaled Kaim.

A Libyan anti-Gadhafi activist who toured Tripoli described scorch marks outside the U.S. facility's windows and a green Libyan flag draped over the roof on one side. The windows in the guard shack at the entrance were smashed, said the activist, who spoke on condition of anonymity for fear of reprisals.

The U.S. evacuated its diplomatic staff at the start of the Libyan crisis, leaving Turkey to represent American interests in the country.

The U.N. reacted to Sunday's attacks by pulling its international staff out of Tripoli. Britain responded by announcing it was expelling the Libyan ambassador to London.
Italy had withdrawn its diplomats weeks ago.

Qaddafi's son Seif al-Arab was reportedly killed Saturday by a NATO strike on a Qaddafi compound in Tripoli. Libyan officials denounced the strike as an assassination attempt and a violation of international law.

NATO acknowledged it had struck a "command and control building," but insisted all its targets are military in nature and linked to Qaddafi's systematic attacks on the population.

"It was not targeted against any individual," NATO spokeswoman Carmen Romero said Sunday, adding the report of the deaths remained unconfirmed.