A bomb exploded outside the Tunisian consulate in Tripoli on Tuesday, causing damage but no injuries, a Libyan security official said, the latest in a rash of attacks on foreign targets in the North African state Reuters reported
Libyan police had no information on the identity or motive of the attackers, and a consulate official declined to comment.
Resentment of Tunisia among remaining supporters of late Libyan dictator Muammar Gaddafi may have been stirred by Tunisia's extradition of his ex-prime minister on Sunday - making him the first senior official from the old regime to be returned for trial under Libya's transitional leadership.
The attacks on embassies and international buildings and convoys in Libya this year have underlined the disorder in the country ahead of its first democratic election slated for July 7, almost a year after rebels toppled Gaddafi.
They have also raised concern about the proliferation of weapons in the oil-exporting state that became readily available to citizens during the anti-Gaddafi uprising.
Tuesday's bomb attack in the Libyan capital charred the Tunisian consulate's rear gate and left a hole in the soil nearby. Curious neighbours gathered outside the consulate to view the damage as police officials examined the scene.
"The security cameras showed a car zoom by carrying four unknown men who threw the bomb at the gate. The Tunisian consulate called us to investigate," said Motassim Billah Abu Hreiba, a police investigator.
The Arab Spring popular uprisings that have ousted four autocratic rulers in the past 18 months originated in Tunisia and spread to Egypt, Libya, Yemen, Bahrain and Syria.
Gunmen stormed Tunisia's consulate in the eastern Libyan city of Benghazi on June 18 to protest against an art exhibition in neighbouring Tunisia which they said insulted Islam.
Earlier this month in Benghazi a convoy carrying the British ambassador was attacked with a rocket-propelled grenade, injuring two of his bodyguards. Just before that, a bomb went off outside the U.S. consulate in Benghazi, injuring no one.