A women's rights organization connected to five feminist activists whose detentions prompted international concern earlier this year says it has been forced to shut down permanently because of mounting pressure from authorities.

Founder Wu Rongrong said Friday that she was "sad beyond words" at the closure of Weizhiming in the eastern city of Hangzhou and that there now would be "even fewer opportunities" to speak out publicly in support of women's rights.

Weizhiming has campaigned against discrimination in the labor market, violence against women and sexual harassment on public transport.

Wu was detained along with four other activists in March, just ahead of International Women's Day, when they were planning to hand out stickers and flyers against sexual harassment in several Chinese cities.