The jihadists include one veteran fighter who had been detained in Britain on suspicion of terrorism. The source describes him as committed to al Qaeda’s global cause and to attacking U.S. interests.

The source told CNN that the al Qaeda leader, Ayman al-Zawahiri, personally dispatched the former British detainee to Libya earlier this year as the Gadhafi regime lost control of large swathes of the country.

The man arrived in Libya in May and has since begun recruiting fighters in the eastern region of the country, near the Egyptian border. He now has some 200 fighters mobilized, the source added. Western intelligence agencies are aware of his activities, according to the source.