A Bahraini rights group says a female activist has been charged under an anti-terrorism law amid a crackdown on dissent in the U.S.-allied Gulf island nation.

The London-based Bahrain Institute for Rights and Democracy said Wednesday that Ebtisam al-Sayegh was one of four people accused of using human rights work as a cover for terrorism-related activities.

The official Bahrain News Agency announced the charges but did not name the suspects. Bahraini officials did not immediately reply to a request for comment.

Al-Sayegh was taken into custody two weeks ago in a late-night raid. Amnesty International has raised concerns, saying al-Sayegh alleges she was tortured and sexually assaulted during an earlier detention in May. Bahrain has said it opposes any mistreatment of detainees.