Hundreds of anti-government protesters have clashed with police and government supporters in Libya's second city, in the latest display of unrest in the Arab world.
Dozens of people are said to have been hurt in the clashes in Benghazi.
The overnight unrest followed the arrest of an outspoken government critic, who was reportedly freed later.
State TV showed demonstrations in several cities said to be in support of Libyan leader Muammar Gaddafi.
The unrest comes a day before planned anti-government demonstrations on Thursday, dubbed a "Day of Anger", which are being organised via internet social networks.
Pro-democracy protests have recently swept through several Arab nations, with the presidents of Tunisia and Egypt forced to resign amid growing unrest.
But Wednesday's demonstrations were the first display of defiance in Libya, where dissent is rarely tolerated.
Witnesses say that at one stage up to 2,000 people were involved in the overnight protests in Benghazi, which saw a march on government offices in the city.