Karman was involved in demonstrations in support of Tunisia's uprising during which calls for political change in Yemen were also made [Reuters]
A court in Yemen has granted parole to a political activist and journalist detained over the weekend on charges of inciting disorder, sources have told the AFP and Reuters news agencies.
Tawakel Karman, who is also a member of the opposition Islamist party al-Islah, was "released with a commitment from her family that she will no longer offend public order and law," a judicial source told AFP on condition of anonymity.
Karman, who heads the Women Journalists Without Chains rights group, was involved in demonstrations in support of Tunisia's uprising during which calls for political change in Yemen were also made.
Shortly before her release, she called for all other protesters, who were arrested in recent days, to be released, and vowed to continue working for political reform in Yemen.
Police arrested her in a main street in Sanaa as she headed home with her husband late on Saturday night, rights activists said.
She was accused of organising "unauthorised gatherings and marches and inciting riots and disorder", the defence ministry's news website 26sep.net reported.
Students hold demonstrations
Mohammed Qobati, a spokesman for Yemen's parliamentary opposition, on Sunday described the arrest as "a criminal offence and an immoral act".
Several hundred students gathered outside Sanaa University after the arrest, demanding her release.
Around 200 journalists marched in Sanaa on Sunday to demand the release of Karman and other detainees, and her arrest was condemned by both Yemeni and international rights groups.
Also on Sunday, 18 opposition activists were arrested and one demonstrator was shot dead by police in the southern city of Aden.
While hundreds of Sanaa University students held rival demonstrations on campus on Saturday, both for and against Ali Abdullah Saleh, Yemen's president.
Since the Tunisian turmoil, Saleh has ordered income taxes slashed in half and has instructed his government to control prices. He also ordered a heavy deployment of anti-riot police and soldiers to several key areas in the capital and its surroundings to prevent any riots.