WASHINGTON (AP):

President Barack Obama yesterday condemned attacks on a US consulate in eastern Libya that killed the US ambassador and three American members of his staff. He ordered increased security at US diplomatic posts around the world.

In a White House statement, Obama said he had ordered "all necessary resources to support the security of our personnel in Libya, and to increase security at our diplomatic posts around the globe."

The attacks occurred Tuesday night in the eastern city of Benghazi by protesters angry over a film that ridiculed Islam's Prophet Muhammad, according to Libya officials. Ambassador Chris Stevens, 52, was killed when he and a group of embassy employees went to the consulate to try to evacuate staff as the building came under attack by a mob with guns and rocket-propelled grenades. Three other Americans were also killed.

Stevens is the first US ambassador to be killed in an attack since 1979, when Ambassador Adolph Dubs was killed in Afghanistan.

The State Department identified one of the other Americans killed Tuesday as Sean Smith, a foreign service information management officer. The identities of the others were being withheld pending notification of next of kin.

In a written statement earlier yesterday, Obama called Stevens a "courageous and exemplary representative of the United States".