Gunmen attacked Libya's Defence Ministry, killing one and kidnapping three soldiers, according to the ministry's statement published on Monday.
The statement did not disclose the identities of the attackers but demanded them to "keep restraint and leave the ministry immediately."
"The Defence Ministry holds the armed groups responsible for the bloodshed and destruction of public property," the statement said.
Intense fighting has been going on in the capital city of Tripoli since early Sunday when Islamist armed groups launched attacks on Tripoli International Airport and some key road intersections.
The Islamist militant groups, some affiliated with the government, said their goal was to expel all militias from the capital Tripoli in a militarized operation dubbed "Libya Dawn." However, the Libyan government issued a statement on Sunday afternoon and condemned the move as "illegitimate."