Authorities detained the women in three cities -- Beijing, Guangzhou and Hangzhou -- a few days ahead of events planned for International Women's Day on March 8.
"Each and every one of us has the right to speak out against sexual harassment and the many other injustices that millions of women and girls suffer around the world," U.S. Secretary of State John Kerry said in a statement Friday.
"We strongly support the efforts of these activists to make progress on these challenging issues, and we believe that Chinese authorities should also support them, not silence them."
The detention of
Wei Tingting, along with Wu Rongrong, Li Tingting, Wang Man and Zheng Churan has drawn harsh criticism from the international community.
Protesters in several cities have called for their release and taken to social media with the phrase "free the five" as a hashtag.
Wang Qiushi, the lawyer for Wei, said police recommended Monday that prosecutors press charges of "assembling a crowd to disturb public order."
Prosecutors have seven days -- until Monday -- to decide whether to pursue the charges, according to the lawyer.
"We can do nothing but wait," Wang said.
The five were initially held on suspicion of "picking quarrels and provoking trouble." Wang said he didn't know why the charge against the women changed.
"Neither should constitute a crime," he said.
Campaign group Amnesty International said the new charge was less serious but still carried a maximum prison term of five years.
"The women were doing nothing wrong, nothing illegal. They were simply calling for an end to sexual harassment," said William Nee, China researcher at Amnesty International.
Wang said that Wei was subjected to lengthy cross examinations during her detention. Two of the women are said to be in poor health.
He added that the charges relate both to the activities the women planned for International Women's Day and earlier campaigns against domestic violence.
The five are members of China's Women's Rights Action Group. They had planned to hand out stickers with slogans saying "stop sexual harassment, let us stay safe" and "go police, go arrest those who committed sexual harassment!" on International Women's Day.
This week, Kerry's predecessor, Hillary Clinton, tweeted
that the activists' detention was "inexcusable."
Chinese authorities rebuked her comment, saying public figures should respect
the nation's sovereignty and independence.