Dozens of protesters broke into the offices of the TV station Libya Al Hurra in the eastern city of Benghazi, reported the independent newspaper Libya Herald on Monday.
The attackers, believed to be from the Warfalla tribe, accused the broadcaster of bias in covering a crackdown by the army on the south-eastern town of Bani Walid, added the report.
Most inhabitants of Bani Walid are Warfallas, dpa reported.
The Sunday night attack disrupted the transmission of the station, which was the first Libyan broadcaster to support the 2011 armed revolt that toppled the regime of Moamer Gaddafi.
The Libyan army on Saturday launched an attack on Bani Walid to arrest suspected rogue militiamen in the town after a siege of more than two weeks.