Arab news channels said Friday the Yemeni authorities had seized broadcasting equipment from their Sana'a bureaux by force because of their coverage of the growing unrest in Yemen's south. A government official told state media that Qatar-based Al-Jazeera television and the Saudi-owned channel Al-Arabiya did not have proper authorization for the equipment seized, and that it would be returned to them eventually. Al-Jazeera said Yemeni security forces had stormed its office in Sana'a Thursday evening after being warned over its coverage of a southern secessionist movement on which the government recently launched a major crackdown. An official had telephoned Al-Jazeera's office earlier Thursday, saying measures would be taken if the channel covered a meeting of southern opposition leaders, Murad Hashim, the head of Al-Jazeera's Sanaa bureau said on the channel's website. Al-Arabiya also reported that some of its broadcasting equipment had been confiscated by police Thursday. Its bureau chief was questioned for two hours but then released, Nasser Al-Sarami, head of media at Al-Arabiya told Reuters. “They are concerned about the way we cover what is going on in the south. They didn't give us a reason, but we believe this is the link,” Sarami said. Thousands gathered for demonstrations across Yemen Thursday to demand an easing of the crackdown in the south. Two people were shot dead as security forces tried to quash a separatist protest in a southern province. Satellite television stations Al-Jazeera and Al-Arabiya are among the most widely watched news channels in the Arab world.