Saad al-Hariri resigned as Lebanon's prime minister on Tuesday, declaring he had hit a "dead end" in trying to resolve a crisis unleashed by huge protests against the ruling elite and plunging the country deeper into turmoil.

Hariri addressed the nation after a mob loyal to the Shi'ite Muslim Hezbollah and Amal movements attacked and destroyed a protest camp set up by anti-government demonstrators in Beirut.