Police arrested 39 Afghans suspected of being Taliban fighters in the southwestern Pakistani city of Quetta, an official said Tuesday. An Islamist group said the detainees were students.

The arrests were made in separate raids on rented houses Monday night and early Tuesday in areas in and around Quetta populated by large numbers of refugees from neighboring Afghanistan, said Chaudhry Mohammed Yaqoob, chief of police in Baluchistan province, whose capital is Quetta.

Pakistan is under U.S. and Afghan pressure to do more to detain Taliban militants or extremists allied to the toppled Afghan regime believed operating in Pakistan. The Pakistani government denies turning a blind eye to such activities, instead saying it is doing its best to crack down on militants.

Police are interrogating the suspects to learn if any senior Taliban figures were among them, Yaqoob said. Afghan officials have alleged Taliban leader Mullah Omar is in Quetta, but Pakistan has rejected the claim.

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A spokesman for a pro-Taliban Islamic group protested the arrests, saying the men were Islamic students and not fighters.

"They came here to study. They have no link with fighting," said Abdul Sattar Chisti of Jamiat Ulema-e-Islam party, a key member of a six-party Islamic political coalition.

Dozens of Taliban suspects, including militants being treated at Quetta hospitals after being wounded in clashes with NATO and U.S. forces in Afghanistan, have been arrested in the city in recent months, with many handed over to Afghan authorities, Yaqoob said.

Pakistan had long supported the Taliban before severing ties with the militia and backing the U.S.-led war on terrorism after the Sept. 11, 2001 attacks in the United States.