TRIPOLI -- US ambassador to Libya Christopher Stevens is confirmed to have died in Tuesday's conflict in the US consulate building in Libya's eastern city of Benghazi, Libyan officials said on Wednesday.

Hundreds of protesters, angered by an alleged US-made movie that insults Prophet Mohammed, broke into the US consulate building in Benghazi on Tuesday night, and set ablaze the building.

Wanis Sharef, a Libyan deputy interior minister in charge of the country's security affairs in the east, confirmed to media on Wednesday that the US ambassador was killed.

The US ambassador, who was on a short trip to Benghazi, died from suffocation as a result of smoke inhalation, as protestors set fire at the scene. Three staffers were also killed during the fierce clashes.

The bodies of the four killed US diplomatic personnel will be transferred to Libya's capital of Tripoli, sources told Xinhua.

Stevens had served as the US representative to Libya's National Transitional Council during last year's unrest that toppled former strongman Muammar Gaddafi before taking up the post as an ambassador in May.

US President Barack Obama on Wednesday strongly condemned the fatal attack that killed the ambassador and three other Americans.

"I strongly condemn the outrageous attack on our diplomatic facility in Benghazi, which took the lives of four Americans," he said in a statement released by the White House.

Sharef told Xinhua that 12-18 people in the American consulate had been injured during Tuesday's attack, and that a total of 32 U. S. diplomatic personnel had been evacuated to safe place.

As Libya's Foreign Ministry and the General National Congress ( GNC) are expected to hold press conferences on the issue Wednesday night, GNC President Mohammed Maqrif has already apologized during a press conference in the capital Tripoli to the United States over the death of the ambassador, adding that no one will escape from punishment.

On Tuesday, several thousands of Egyptians also protested in front of the US embassy in the capital Cairo against the same movie, allegedly sponsored by Americans but not by US government or Hollywood industries.