Security guards at Libya's parliament have beaten up a crew of Alassema, an independent television network, the channel told AFP on Sunday.
"A team from (Alassema TV) went to cover a meeting of the national assembly on Friday, entering as they were permitted to," the channel's press office director Fethi Ben Aissa said.
"After interviewing an MP, the team was assaulted by plain clothes guards of the General National Congress," he said, adding that "the public prosecutor has decided to open an inquiry into the incident."
A video posted on the Internet, purportedly of the same incident, showed a cameraman being pushed and hit by men in civilian clothing, provoking an online uproar.
A joint statement by dozens of journalists said "this act of aggression essentially constitutes an attack against freedom of the media and is a return to the era of the stifling of the press."
It called for "the creation of a journalist union ... to ensure the defence of people's rights to obtain correct and timely information from different media outlets."
Under the regime of slain dictator Moamer Kadhafi, who was ousted by a popular uprising in 2011, independent media outlets and any criticism of government were banned.