Saudi women’s rights activists detained last year in a sweeping crackdown on campaigners will be put on trial, prosecutors have said.

“The public prosecution would like to announce that it has concluded its investigation and prepared the indictment list against the defendants ... and will refer the case to the relevant court,” the state-controlled Saudi Press Agency said on Friday.

The brief statement did not directly identify the defendants as female activists nor give a date for court proceedings.

More than a dozen activists were arrested in May last year – just before the historic lifting of a decades-long ban on female drivers the following month. Many of them were accused of undermining security and aiding enemies of the state. Some were subsequently released.

Those still detained include Aziza al-Yousef, a retired professor at Riyadh’s King Saud University, and Loujain al-Hathloul – who was held in 2014 for more than 70 days for attempting to drive from neighbouring United Arab Emirates to Saudi Arabia.

Some of those detained have faced sexual harassment and torture during interrogation, rights groups and their family members say. Several people with knowledge of their arrest have told the Associated Press that some of the women detained have been subjected to caning, electrocution and others were also sexually assaulted.

In February a cross-party panel of three British MPs found the female activists were being detained in cruel and inhumane conditions that meet the threshold of torture under both international and Saudi law.

Friday’s statement from prosecutors said “all detainees in this case enjoy all rights preserved by the laws in the kingdom”.

But the statement drew sharp criticism from human rights groups.

“These women’s rights activists should be released from detention for their peaceful activism not referred to trial,” Samah Hadid, Amnesty International’s Middle East campaigns director, said. “The Saudi Arabian authorities continue their signature repression.”

Michael Page, the deputy Middle East director at Human Rights Watch said: “The Saudi prosecution is bringing charges against the women’s rights activists instead of releasing them unconditionally.

“The Saudi authorities have done nothing to investigate serious allegations of torture, and now, it’s the women’s rights activists, not any torturers, who face criminal charges and trials.”

Agence France-Press and Associated Press contributed to this report