Pakistani security forces are on high alert in the capital, where Islamic students kidnapped four policemen.
The incident is the latest challenge to the government from the radical "Red Mosque."
A spokesman for Pakistan's Interior ministry, Brigadier Javed Iqbal Cheema says the four officers were taken Friday from the main road outside the Lal Masjid mosque in central Islamabad.
He says 15 to 20 students from the nearby seminary kidnapped the unarmed policemen as they drove past the mosque.
The mosque's pro-Taleban clerics say the officers were conducting undercover surveillance of the area, despite a prior agreement that police would avoid the neighborhood.
The mosque's religious leaders and thousands of their supporters have repeatedly challenged government authority in recent months.
Its top clerics have vowed to impose Taleban-style Sharia law in the capital and have threatened massive suicide bomb attacks if the government tries to interfere.
Students from the mosque's religious seminaries swept through one of Islamabad's main market areas last month, warning shop owners against selling music or movies.
Hundreds of students have also been occupying a nearby children's library since January to protest government efforts to demolish several mosques illegally built on government property.
The government had been trying to avoid direct confrontation with the mosque.
But government critics say the authorities are appeasing pro-Taleban militants and allowing religious extremists to gain a foothold inside the Pakistani capital.
The government is also under pressure in northwestern Pakistan, where at least eight government officials, including five women, were kidnapped Friday.
Authorities in North Waziristan say more than a hundred tribal gunmen abducted the government development workers near the Afghan border.
The government officials were preparing plans for local aid projects.