Gunmen on Monday demanded the Libyan government's resignation as they besieged ministries despite the adoption of a law to purge officials from the regime of dead dictator Muammar Gaddafi from their posts.

"We are determined to continue our movement until the departure of (Prime Minister) Ali Zeidan," said Osama Kaabar, a leader of the militias who had promised to lift their siege if the law was passed.

The General National Congress, under pressure from the gunmen, on Sunday voted through the controversial law to exclude former Gaddafi regime officials from public posts in a move that could see the premier removed from office.