About 150 workers at a textile factory in the capital, Sanaa, were on Saturday striking for unpaid wages at their workplace, not far from a home of President Abdullah Saleh when the violence occurred.
About 200 police surrounded the journalists and beat Mujib Swailih, a cameraman for the Dubai-based Al-Arabiya network.
Hamud Munasil, the head of the Al-Arabiya office in Sanaa, said Swailih's injuries were serious.
Najib al-Sharibi, a correspondent for the Saudi government-run Al-Ekhbariya satellite network, also suffered minor injuries.
"Mujib Swailih was beaten with truncheons several times" by police deployed in force around the sit-in before being taken to a police station where the cameraman "was insulted", one of the station's employees said.
Swailih was released after several hours and taken to hospital.
Dubai-based Al-Arabiya denounced what it said was "a hostile mobilisation campaign towards journalists, particularly correspondents from foreign media, targeted by defamation in government newspapers" in Yemen.
"Mujib Swailih was beaten with truncheons several times"
Unnamed Al-Arabiya employee
Yemeni police were not immediately available for comment.
Yemeni newspaper editor Jamal Amir said in August that he had been abducted and beaten by armed men claiming to act on behalf of military officers and wanting to know about his sources.
Journalists have reported a concerted campaign of abuse and harassment by the government in recent weeks.
Al-Thawra, the government-run daily newspaper, has carried editorials over the past several days accusing reporters of being "agents of foreign intelligence networks" that seek to hurt Yemen's image by claiming that it harbours terrorists.