EGYPTIAN Foreign Minister Amr Mussa flew to Tripoli in violation of an air embargo after Britain and the United States withheld permission for the flight, sanctions committee sources said on Tuesday.The sources said that Egypt notified the United Nations sanctions committee at the weekend in advance of Monday’s return flight from Cairo.But the United States blocked the flight, and Britain delayed authorization while seeking further information about whether the flight had a humanitarian motive.The UN Security Council imposed an air and arms embargo against Libya in 1992 to press for the handover of two Libyan suspects wanted for their role in the bombing of a US airliner over Lockerbie, Scotland in December 1988.