GENEVA- The U.N. human rights office called on Tuesday for the release of four women activists and their relatives in Afghanistan who were detained or abducted last month after protests over women's rights since the Taliban seized control.

The OHCHR said there was no news about the whereabouts of the four women, who it said reportedly took part in a protest on women's rights on Jan. 16, and added it was pressing the authorities for information on these cases.

"We call for their immediate release," Liz Throssell, an OHCHR spokesperson, told Geneva-based journalists. "We are gravely concerned for the safety of the disappeared women and their family members."

The OHCHR said Parwana Ibrahim Khil and Tamana Paryani were abducted with their relatives on Jan. 19, while Mursal Ayar and Zahra Mohammadi were seized last week and there was no information on where they were being held.

Throssell said it was unclear who had taken the women and noted Taliban officials had denied involvement.

Asked to respond, Taliban administration spokesman Bilal Karimi said: "Still we are investigating and trying to find information."

Fears for the safety of vocal opponents of the Taliban and prominent women have risen since the Islamist group took over the country in August as foreign forces withdrew. Many civil society and women's rights activists fled the country.

The Taliban says they have an amnesty for any previous opponents and that they respect women's rights in line with Islamic law and customs, but many human rights advocates and foreign diplomats remain sceptical.

(Reporting by Emma Thomasson; Additional reporting by Kabul newsroom; Editing by Miranda Murray and Alison Williams) ((+4930220133580;))