A Shiite rebel spokesman said Yemen authorities have released hundreds of rebel detainees.
Mohammed Abdel-Salam said at least 428 Hawthi detainees were freed on Thursday.
Abdel-Salam said the release was mediated by Qatar, which brokered a cease-fire between President Ali Abdellah Saleh's government and the Hawthi rebels last February.
The Hawthi Shiite tribesman in Yemen have waged an on-and-off struggle against the government for the last six years.
Prisoner releases come periodically.