Yesterday US Secretary of State Hillary Clinton said the Algerian militants involved in the attack on a desert gas plant had weapons from Libya.
"There is no doubt that the Algerian terrorists had weapons from Libya. There is no doubt that the Malian remnants of AQIM have weapons from Libya."
AQIM - Al Qaeda in the Islamic Maghreb - is an affiliate of al Qaeda.
Hillary Clinton was testifying before the Senate Foreign Relations Committee about the September attack by Islamist militants in which the US ambassador and three other Americans were killed in Benghazi.
Air Malta has cancelled its flights to Benghazi on Thursday following the Foreign Office's advice for Britons to leave.
In a statement on the website the airline said:
Whilst Air Malta regrets any inconvenience caused, the airline will always place the safety and security of its staff and customers as its highest priority.
British nationals have been advised to leave Benghazi in Libya, just a week after four Britons were killed in a terrorist attack in In Amenas, Algeria.
Foreign Office minister David Lidington, told the BBC that the risk of terrorism in the region has been ongoing for some time but that the Foreign Office would not issue its current advice to leave if there were not serious reason to do so.
The terrorism risk has been there for some time, before Mali and before the Algeria crisis of last week.
I cannot comment further on operational matters but the safety of Britons is our primary concern at the Foreign Office.
We only issue the kind of advice we have, to leave Benghazi, if we have information on a credible and imminent threat.
The Foreign Office spokesman said: "We cannot comment further on the nature of the threat at this time."
Benghazi was the stronghold of the Western-backed revolt that eventually ended Gaddafi's hold on power in Libya.
However, Britain has not had any diplomatic presence in the city since an attack on the US mission last September that killed American ambassador Chris Stevens and three of his colleagues.
The Foreign Office has been advising against travel to most of Libya since last September, but has now stepped up its warning.
We are now aware of a specific and imminent threat to westerners in Benghazi, and urge any British nationals who remain there against our advice to leave immediately.
We have updated our travel advice to reflect this. The British Embassy in Tripoli has been in contact with British nationals for whom we have contact details to alert them to the advice.
The Foreign Office today urged British nationals to leave Benghazi in Libya "in response to a specific threat to westerners".
As she began her testimony, her voice cracked at times as she said her work is sometimes highly personal, she told the Senate Foreign Relations Committee:
I stood next to President Obama as the Marines carried those flag-draped caskets off the plane at Andrews. I put my arms around the mothers and fathers, sisters and brothers, sons and daughters.
At another point, she defended UN Ambassador Susan Rice, who was vilified for widely debunked claims five days after the attack that protests precipitated the raid rather than terrorism. She challenged the Republican focus on Rice's comments, which were based on intelligence talking points.
"What difference does it make?" a clearly exasperated Clinton told Sen. Ron Johnson, a Republican, after he pressed her. She insisted that "people were trying in real time to get to the best information," and that her focus was on looking ahead on how to improve security.
President Obama has said the United States has some "very good leads" about who carried out the attacks in Benghazi, Libya, in September that killed four Americans including the US ambassador.
Obama told NBC's 'Meet the Press' that the US would "implement every single recommendation" put forward in an independent review of the Sept. 11 attack on the consulate in which Ambassador Chris Stevens was killed.
"We're not going to pretend that this was not a problem. This was a huge problem," he said, adding that the investigation into who carried out the deadly raid was "ongoing."
"The FBI has sent individuals to Libya repeatedly. We have some very good leads, but this is not something that I'm going to be at liberty to talk about right now," he added.