500 Britons left Libya by plane and boat on Thursday, describing the situation in the country as terrifying. However, according to the Foreign Office, at least 220 Brits remain trapped in Libya. The SAS has now been put on standby.

Three British RAF planes are assisting in the evacuation of stranded Britons while Royal Navy frigate, HMS Cumberland, has departed from Benghazi, rescuing around 200 people, of various nationalities.

A US ferry is expected to follow suit today, evacuating at least 275 people.

The SAS had been put on standby for an “emergency deployment”, reports the BBC.

However, the Foreign Office said there were up to 220 Britons still in Libya. About 50 in and around Tripoli and up to 170 oil workers stranded in desert areas.

Those returning from Libya brought tales of terror and violence.

Oil worker Stephen Willoughby was among the first 70 Britons to return from Libya, on a plane chartered by oil company BP.

He told Sky News: “It has been horrific. Thousands and thousands are just trying to get home. There was a stampede last night, tear gas was thrown.

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“There was just constant shooting. You didn’t fear for your safety but there has just been constant gunfire over the last 72 hours.”

The Foreign Office is advising against all but essential travel to Libya as the standoff between protesters and the Libya’s long-term ruler, Moammar Gaddafi, continues. The unrest is spreading toward the capital, Tripoli.

Prime Minister David Cameron is due to chair a meeting of the National Security Council later. The PM has already said he is “incredibly sorry” for his slow handling of the evacuation.

The evacuation of Britons from Libya continues today.

UK nationals wishing to register an interest in flights out of Libya should call 020 7008 0000 from the UK or 021 3403644/45 from Libya.