Pro-Taleban Islamic students said on Saturday that they would release two of the four police officers they took hostage in Islamabad on Friday.
A senior cleric Abdul Tashid Ghazi at the radical Lal Masjid, or Red Mosque, said the government has agreed to free several detained seminary students in exchange for the hostages.
Government confirmation of the deal was not immediately available.
Pakistani authorities are still trying to negotiate the release of the other two captives.
A spokesman for Pakistan's Interior Ministry Brigadier Javed Iqbal Cheema said about 15 Islamist students kidnapped the four unarmed policemen Friday as they patrolled outside Lal Masjid in central Islamabad.
In an interview with Pakistani television (Aaj) broadcast late Friday, President Pervez Musharraf said Islamic militancy is on the rise, and that strong measures must be taken to counter it.
Elsewhere, Pakistani officials said on Saturday suspected Islamic militants ambushed a government vehicle and kidnapped eight officials. The incident occurred late Friday in North Waziristan, near the Afghan border.
There was no immediate claim of responsibility.
Authorities say the government officials were traveling from the city of Peshawar to inspect development projects in the region, which is a haven for both Taleban and al-Qaida militants.