Rubble is all that's left of this police station in Libya's eastern city of Benghazi.

The Wednesday blast flattened the building and shattered windows nearby, however, no casualties were reported.

It had been emptied for repairs following previous attacks, say authorities.

This security official described the bombing as "extreme terrorism", adding that the explosives were set by professionals.

The same station was set aflame last month in a possible act of revenge over the killing of a man during a separate attack on officers.

Libya's government is still struggling asset its authority as tensions between officials and rebel fighters turned militias rise of late.

Benghazi has become a flashpoint for this kind of violence and has witnesses a recent wave of attacks on security forces.