A car bomb has exploded outside the Swedish consulate in the Libyan city of Benghazi, seriously damaging the building but causing no casualties, according to security official.

The Swedish mission is one of the few remaining diplomatic offices remaining in Benghazi, the hub of the 2011 uprising that toppled long-time ruler Muammar Gaddafi.

"A powerful explosion in front of the Swedish consulate caused serious damage to it and neighbouring buildings but no casualties," Colonel Abdullah Zaidi, the security official, said.

It is located in Benghazi's Al-Fouihet district, not far from the Egyptian consulate, which was bombed in August.

Nobody claimed responsibility for Friday's attack, which occurred just days after a US special forces' raid captured a Libyan al-Qaeda suspect in Tripoli.

Benghazi has been hit by a wave of attacks against government offices and targeted killings in recent months as security agencies struggle to secure Libya since the 2011 civil war.

Weapons have proliferated and a number of rebel fighters have vied for authority, operating with impunity.

Some rebels have warned of possible retaliation against American interests - or even other foreigners - after the recent US raid in Libya in which the al-Qaida suspect was seized and transported out of the country.

The raid angered rebel fighters who accuse the Libyan government of colluding in the abduction of a Libyan citizen.

Fighters attacked the US consulate in Benghazi last year, killing the US ambassador and three other Americans.

Source: Agencies