France's heavy involvement in North Africa, including its joint leadership with Britain in the aerial bombardment which supported the rebel overthrow of Col Muammar Gaddafi in Libya in 2011, has made it the principal target of militant activity in the region. Seven members of the same French family seized in Cameroon were released on Friday, but a further seven French nationals are in the hands of kidnappers linked to Al-Qaeda in North and West Africa. Tuesday's explosion damaged houses along the street occupied by the embassy in the upmarket Hay Andalus area of the city. The twisted wreckage of the car used in the attack was lying in the middle of the street. The attack was condemned by the French president, Francois Hollande, and the foreign minister, Laurent Fabius, was expected fly to Tripoli later in the day. "France expects the Libyan authorities to shed the fullest light on this unacceptable act, so that the perpetrators are identified and brought to justice," Mr Hollande said. Libya's foreign minister, Mohammed Abdul Aziz, visited the embassy, where a reception had been held on Monday night for two visiting French MPs. Investigators will focus on a number of militias and extremist Salafi groups operating in the country, including Ansar al-Sharia, which United States officials say has been in contact with AQIM. Its members were identified as among those attacking the US consulate in Benghazi last September, when the American ambassador, Chris Stevens, was killed. There has been no progress in attempts to bring those reponsible to justice, something which has strengthened fears that violent groups in the country can operate with impunity. That was only the worst attack on foreign interests. The car of the then British ambassador, Sir Dominic Asquith, was also attacked in Benghazi, while Christian sites, including Commonwealth war graves and Egyptian churches have also been targeted.