Two large explosions hit courthouses in the city of Benghazi late Sunday, leaving part of one of the buildings a pile of rubble, two security officials said.
An official in Benghazi said 10 people were wounded, two seriously, in the explosion outside one courthouse. Video posted by residents online showed several vehicles destroyed by that explosion. The video also showed residents standing in a crater in the ground outside the building.
Another courthouse in the eastern part of the city was also hit, said a security official in the capital, Tripoli.
The courthouse in the north of Benghazi was the site of the first protests against dictator Moammar Gadhafi in early 2011 that led to his ouster. It continues to be a hub for protests.
The explosion erupted just before a planned protest outside one of the buildings to mark the second anniversary of the death of Gen. Abdul Fattah Younis, a former Gadhafi security minister who defected from the regime to join the rebels fighting him. He was killed in July 2011 by his comrades while in custody after he was arrested on suspicion of treason.
Security officials said police are investigating if the explosions were the result of bombs. They spoke anonymously because they were not authorized to speak to media.
The city of Benghazi was the birthplace of the country's uprising against Gadhafi's rule and is also Libya's second largest city.
Benghazi's security is among the most precarious in post-revolution Libya. Last year, U.S. Ambassador Chris Stevens and three other Americans were killed in an attack on a U.S. diplomatic mission in the city.
Police there have also been involved in attacks and clashes last month between protesters and a government-aligned militia that left 31 people dead in the eastern city.
On Saturday, a prison break there set more than 1,000 inmates free. Inmates started a riot and set fires after security forces opened fire on three detainees who tried to escape on Saturday, a security official at al-Kweifiya prison said. Gunmen quickly arrived to the prison after news of the riot spread, opening fire with rifles outside in a bid to free their imprisoned relatives, a Benghazi-based security official said.
Those who escaped either faced or were convicted of serious charges, the prison official said. High-risk detainees charged or imprisoned for extremist ties had already been transferred to a more secure prison in the capital, Tripoli, before the prison break, the official said.
Special forces said they arrested 18 of the escapees, while some returned on their own, said Mohammed Hejazi, a government security official in Benghazi.