HONG KONG (AP) — A pro-democracy group in Hong Kong says well-known activist Joshua Wong has been arrested.

Demosisto posted on its social media accounts that Wong had been pushed into a private car around 7:30 a.m. Friday and was taken to police headquarters. It later said another member, Agnes Chow, had been arrested as well.

Police did not immediately confirm either arrest.

Wong is secretary-general of the group and was one of the student leaders of major pro-democracy demonstrations in 2014.

He was released from prison in June after serving a two-month sentence related to that protest. He has been speaking out regularly in support of the pro-democracy protests that have racked Hong Kong this summer.