A car bomb has exploded near the offices of the military police in the Libyan capital Tripoli.

It is the first such attack in the city since the start of the popular revolt that toppled Muammar Gaddafi last year.

A senior security source said the blast had slightly wounded a Tunisian national, but there was no word yet on who was behind the attack.

It is the latest in a series of violent incidents in the country in recent days but these have been mostly confined to the east of Libya.

Seven Iranian relief workers were abducted in Benghazi on Tuesday by an armed group.

The Libyan Red Crescent Association is currently trying to get them released.