A Yemeni human rights group said on Thursday it was concerned by a string of arrests of activists and academics in south Yemen, where a crackdown on protests demanding the president's resignation has been most severe.
President Ali Abdullah Saleh, a U.S. ally against al Qaeda's Yemen-based wing, who has ruled this fractious Arabian Peninsula state for 32 years, is struggling to quell daily protests that have drawn tens of thousands to the streets across the country.
Activists in the south, which was once an independent state, say police reaction to their protests has been more violent and say security forces have clamped down on movement in the south.
The Yemeni Organisation for the Defence of Human Rights and Democratic Freedoms said five political and human rights activists, as well as an academic and an engineer, were arrested in the second wave of arrests this week. Five southern activists were arrested on Sunday.
"These violations of human rights by security forces in the south have crossed the line," the organisation said.
"We demand a stop to the chasing and terrorising of activists without obtaining legal warrants," the Yemeni rights group said, adding that it had no information on where the detainees had been taken.
Government officials contacted by Reuters declined to comment.
Saleh, who has also faced an on-and-off war with Shi'ite Muslim insurgents in the north, has long struggled to curb a secessionist rebellion in the south.
North and south Yemen united in 1990 and the uneasy merger brought civil war four years later, but Saleh's forces crushed the separatists and reunited the country.
Many in the south, which holds most of the country's dwindling oil reserves, complain that northerners take their resources and deny them political participation.