The attack on the US Embassy in Libya, which killed Ambassador Christopher Stevens and 3 other officers, was the work of about 20 militants, trained to carry out military assaults.

The news that the US Consulate in Benghazi was attacked by trained militants was reported Thursday by the Bulgarian news agency BTA, citing DPA.

According to the Libyan Ministry of the Interior, the assailants used a demonstration against a US-made film offensively depicting Islam's Prophet Muhammad to carry out the deadly attack with a rare rocket-propelled grenade.

The probe is now focusing on finding out if the assault was a planned act by an Al Qaeda-inspired organization to mark the anniversary of the September 11 terrorist attack on the US, since it happened on the same date.

Security measures have been increased for all American Embassies across the globe. The Pentagon sent two battleships to the Libyan coast.

US President, Barack Obama, strongly condemned the act and vowed the perpetrators will be found and will face a Court trial. He says the US has always respected all religions and there is no excuse for such senseless violence.

The initial lead was that the attack was a spontaneous outburst of people outraged by the said film which can be seen on YouTube.

The film, titled "The Innocence of Muslims" portrays Prophet Muhammad as a religious cheat and a womanizer.

The filmmaker, who identified himself in a telephone interview with The Associated Press as Sam Bacile, said he is an Israeli-born, Jewish writer and director, living in California.

According to CBS, there is no evidence that Bacile, who is said to be into hiding, is a real person. In an interview for the TV channel, a man, Steve Klein, who presented himself as a consultant for the film, has said the director is concealing his real name while the aim of the creators has been to expose radical Islamists.

Klein rejected the information the director is Israeli-born, stating he did not know his real name, but it was definitely not Sam.

Meanwhile the Bulgarian National Radio, BNR, and BBC report tensions and clashes near the US Embassy in Cairo, Egypt, during a protest rally against the film. 26 people have been injured.

There had been also protests at the US Embassies in Tunisia and Morocco.

The last time an American ambassador was killed by terrorists was in 1979, when the envoy to Afghanistan, Adolph Dubs, was kidnapped and killed during an attempt to rescue him, recalls the CNN.

We need your support so Novinite.com can keep delivering news and information about Bulgaria! Thank you!