The nine people were kidnapped from a house in a residential neighbourhood of the city.
A private security guard outside the house said that "Taliban students" had come and taken away Chinese residents.
Some reports said that the students, armed with sticks and including 10 burqa-clad women, had abducted the women from an accupuncture clinic which the students said was being used as a brothel.
The students said they had "not kidnapped anyone but have brought six foreign women and three men to persuade them" to change their ways.
"It is a natural reaction by students against vulgarity and obscenity," the students said.
Kamal Hyder, Al Jazeera's correspondent in Pakistan, said: "The authorities are now confident they are going to strike a deal with the madrassa to release these women unharmed."
Abdul Rashid Ghazi, a religious leader at the mosque, was repoted by the Retuters news agency as saying: "We greatly respect Pakistan-China friendship, but it doesn't mean that foreign women can come here and indulge in such vulgar activities.
"We had complaints that these women did massage for men, but it was more than that," he said.
The Pakistani authorities have been locked in a confrontation with leaders and students at the mosque for months.
The continuing activities of the students have concerned many residents in Pakistan's cosmopolitan capital.
"Vulgarity and obscenity"
|Abdul Rashid Ghazi is one of the |
religious leaders at the mosque [AFP]
In January, female 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 continue to occupy the library.
In March, the students abducted three women they accused of running a brothel, held them for several days and released them only after they had "confessed" in front of reporters.
They have also abducted and briefly held policemen and have warned video shops to stop selling Western films that the students say are obscene.
The mosque's authorities are said to have close to 5,000 followers drawn from associated madrasas.
Fears of a backlash if any of the female students were hurt in any assault on the mosque has stayed the government's hand, according to Pervez Musharraf, Pakistan's president.