At least two people were killed when three car bombs exploded near interior ministry and security buildings in the Libyan capital, the first lethal attack of its kind since Muammar Gaddafi's fall last year.
The first bomb blew up near the interior ministry's administrative offices in Tripoli but caused no casualties.
On arriving at the site of the explosion, police found another car bomb that had not blown up.
Minutes later, two car bombs exploded near the former headquarters of a women's police academy, which the defence ministry has been using for interrogations and detentions. That bomb killed two people and wounded two.
The buildings targeted by the bombers are in residential areas at the heart of the capital, Tripoli.
The blasts took place early in the morning as worshippers prepared for mass morning prayers marking Eid al-Fitr, the Muslim celebration that marks the end of the fasting month Ramadan.
Sporadic violence has remained a problem in Libya despite the peaceful transfer of power to the new government after elections in July, the first in decades following the overthrow last year of Muammar Gaddafi after 42 years in power.