Israel said on Wednesday it regretted the deaths of four U.N. military observers in southern Lebanon and would investigate the air strike that killed them.

French soldiers from the United Nations Interim Force in Lebanon (UNIFIL) evacuate a family in an armored vehicle in Naqura on the south Lebanon coast from a zone where there is heavy fighting along the Israeli border. An Israeli air raid on south Lebanon killed as many as four UN observers, overshadowing an international crisis meeting due to open in Rome, as Hezbollah vowed to fire rockets further into the heart of Israel.[AFP]

"Israel sincerely regrets the tragic death of the U.N. personnel in south Lebanon," said Israeli Foreign Ministry spokesman Mark Regev.

"We do not target U.N. personnel and, since the beginning of this conflict, we have made a consistent effort to ensure the safety of all members of (the U.N. peacekeeping force). This tragic event will be thoroughly investigated," said Regev.

U.N. Secretary-General Kofi Annan had called on Israel to investigate the "apparently deliberate targeting" by Israeli forces of the U.N. observer post where the four were killed.