Australia on Friday joined Britain, Ireland,Germany and the Netherlands in urging its citizens in the Libyan cityof Benghazi to leave. The advisory was Canberra's response to what the British Foreign Office has called a "specific and imminent threat" to Westerners in Benghazi. The Department of Foreign Affairs said embassy staff in Cairo had begun phoning Australians in Benghazi, advising them to leave the city as soon as they could. Benghazi was the centre of the Libyan uprising in 2011 and last year witnessed the attack that killed the US ambassador to Libya,Christopher Stevens.