Hardline religious students from a mosque in Pakistan's capital, Islamabad, kidnapped nine people including six foreign women early on Saturday, accusing them of "immoral activities", the students said.
The abductions were the most provocative action by the Taliban-supporting students associated with the Lal Masjid, or Red Mosque, that they have undertaken since January to press for various demands.
"The foreign women were involved in prostitution in a massage centre," the students said in a statement.
Police confirmed some people had been abducted but said they had no details. The News newspaper reported that Chinese nationals were among the abducted people.
Pakistani authorities have been locked in a confrontation with clerics and students at the mosque for months. The radicals have threatened suicide bombings if force were used to break up their movement.
Trouble began in January when female religious students attached to the mosque occupied a children's library next to their religious school to protest against a city campaign to remove mosques built illegally on state land.
The government stopped the campaign but the students still occupy the library.
In March, the students abducted three women they accused of running a brothel and held them for several days before forcing them to confess in front of reporters and releasing them.
They have also abducted and briefly held policemen and have warned video shops to stop selling Western films the students deem obscene.
The behaviour of the students, reminiscent of the Taliban in Afghanistan, coupled with the authorities' failure to rein them in, has dismayed many residents of the country's relatively cosmopolitan capital.
Followers of the Lal Mosque have become increasingly bold in their self-styled anti-vice campaign.
The nine people were kidnapped from a house in a residential neighbourhood of the city. A private security guard outside the house said "Taliban students" had come and taken away the "Chinese" inhabitants.
Chinese embassy officials were not immediately available for comment.
The students said in their statement they wanted to persuade the foreigners to give up their ways.
"We have not kidnapped anyone but have brought six foreign women and three men to persuade them," they said.
"It is a natural reaction by students against vulgarity and obscenity."
President Pervez Musharraf has said he felt humiliated by his inability to oust the radicals, who have close to 5,000 followers drawn from associated madrasas.
Fears of a backlash if any of the female students were hurt in an assault has stayed the government's hand, according to the president.
Instead of cracking down, the government has sought to appease the radicals by telling them that their grievances will be dealt with.