Two more police stations were attacked in Libya's eastern city of Benghazi in the early hours of Sunday morning, the local council said, after two others were bombed on Friday.
The attacks are the latest signs of insecurity in Libya's second city, birthplace of the uprising that toppled the dictator Moammar Gadhafi in 2011.
Nearly two years after his fall, rebel groups that helped to overthrow him are still refusing to disband and remain a more visible presence on the streets than the state security forces.
"We are not satisfied with the performance of the Ministry of Interior," said Osama Al Sharif, Benghazi's local council spokesman. "And especially with the leadership of Benghazi's police."
The recent violence against diplomats, military and police includes an attack in September that killed the U.S. ambassador and three other Americans.
This week, diplomats began to withdraw from the capital Tripoli, where security took a turn for the worse in late April when armed groups seized two ministries for about a fortnight to press demands on parliament.