Yemen arrested 19 anti-government activists on Sunday, including a prominent woman who led student rallies against the president last week, in a clampdown which sparked a fresh protests in the capital.
Demonstrations broke out across Yemen last week as citizens dissatisfied with the rule of President Ali Abdullah Saleh drew inspiration from the recent ouster of Tunisia's long-time president.
Tawakul Karman, a journalist and member of the Islamist party Islah who organised the protests through text messages and emails, was taken into custody by police on her way home early on Sunday and charged with unlawfully organising demonstrations, her husband told Reuters.
Later in the day, police in Sanaa arrested 18 other activists, including the heads of two of Yemen's largest human rights organisations, as they left a meeting to discuss Karman's arrest.
The arrests sparked a spontaneous protest of several hundred at Sanaa University on Sunday. The demonstrators, chanting "release the prisoners" and holding pictures of Karman, tried to march to the General Prosecution Office, which a security source said had ordered her arrest.
But roughly 50 riot police carrying batons beat them back. Police also beat up two TV cameramen filming the protests and confiscated their cameras, a witness said. One was briefly arrested.
"I have no accurate information about her whereabouts," Karman's husband Mohamed Ismail al-Nehmi said by phone. "Maybe at the central prison, maybe somewhere else, I don't know."
In a speech aired on state television on Sunday, Saleh reiterated an offer of dialogue with opposition groups.
"We are a democratic country and not Tunisia which had placed mosques under surveillance and shut everyone's mouth," he said.
In an move to calm discontent, Saleh also announced plans to raise the salaries of government employees and military personnel by $47 to $234 a month -a good bonus for poorly paid soldiers and civil servants in the Arab world's poorest country.