BENGHAZI: Washington sent destroyers and Marines to Libya after its ambassador was killed, amid speculation the US consulate in Benghazi was attacked by Al Qaeda affiliates rather than by a  frenzied mob. 

A detachment of 50 Marines was dispatched to secure the main American embassy in the Libyan capital Tripoli, where staff numbers were being cut to  emergency levels, United States officials said.    

The US also began evacuating all its staff from its mission in Benghazi, where 52-year-old Ambassador Chris Stevens and three other Americans were killed on Tuesday.    

President Barack Obama warned on Wednesday that no act of terror would dim the values “indispensable” America  offers the world. 

Republican Senator John McCain accused Obama of pursuing “a feckless foreign policy” that has compromised American influence around the world.

US diplomatic staff were plunged into mourning, shocked and stunned that one of their own had fallen.

Under a warm late summer sun, hundreds streamed into the south courtyard at the State Department, where Obama paid a rare visit from the White House to join Clinton in consoling the tight-knit diplomatic community.    

Senior Obama Administration officials said the Marine unit was being flown from their base in Europe.

This is in addition to two US warships — USS Laboon and USS McFaul — which are now being moved to the coast of Libya.

The warships are equipped with Tomahawk missiles that could be used if the Obama Administration orders a strike against those responsible for the attack on US mission.

The crews of each warship equal approximately 300 people.

Pentagon spokesman George Little declined to comment on specific ship movements but said precautionary steps are being taken by the US military.

“The Fleet’s Anti-terrorism Security Teams (FAST) that we deploy when requested are responsible for the protection of Embassy personnel and property, and they also play a role in the evacuation of personnel, as required,” the senior administration official said on condition of anonymity.

“Whether or not US military personnel will be involved in future operations to track down the perpetrators of this attack, I’m simply not going to speculate on what may or may not be in the works in the future,” Little said.

According to Little, the Department of Defence is working closely with the White House and State Department to provide all necessary resources to support the security of US personnel in Libya.

The two destroyers were sent to “the vicinity of Libya” as a  precautionary measure, a senior US official said.   

“Make no mistake, we will work with the Libyan government to bring to justice the killers who attacked our people,” Obama said, while ordering increased security at US diplomatic missions around the world.    

Obama offered a passionate and patriotic defence of US values after his Republican election foe Mitt Romney accused his administration of apologising  for American founding principles and promulgating a weak foreign policy.   

“We want to send a message all around the world to anybody who will do us  harm — no act of terror will dim the light of the values that we proudly shine  on the rest of the world,” the president said.   

“No act of violence will shake the resolve of the United States of  America,” he warned at the start of a campaign event in Las Vegas, Nevada.    

Agencies