Authorities made several arrests in the case of the Taliban school attack that killed 148 in the northwestern city of Peshawar, on Sunday, officials said.
"Quite a few suspects who were facilitators in one way or the other have been taken into custody," interior minister Chaudhry Nisar Ali Khan said, adding that the interrogations were "moving ahead in a positive manner." He did not disclose their identities or say how many they were.
It was also reported that Pakistan's security forces arrested more than 300 terror suspects, including foreigners, in the capital Islamabad.
Seven Taliban gunmen wearing explosives belts stunned the world on Tuesday by storming into a military run school in Peshawar and slaughtering 148 people, including 132 students. Another nearly 121 students were wounded in the ensuing eight-hour siege of the school, located in an area where many military families live.
The group claims it fights to establish a ruling system based on its own harsh brand of Islam. It has killed thousands over nearly a decade.
The Taliban say they attacked the school in revenge for an army operation against them in North Waziristan, launched in mid-June. The army says it has so far killed over 1,200 militants in the operation.
The government bombed the militants' hideouts in country's tribal area along the Afghan border in response, and also lifted a ban on the execution of convicted terrorists.
Over the weekend, it executed six men convicted on terrorism charges.
Two of the convicts were hanged on Friday, and another four on Sunday, according to two Pakistani government officials who spoke on condition of anonymity because they were not authorised to brief reporters.
All six belonged to local Pakistani militant groups who had turned against the state, and were convicted for involvement in two attempts to assassinate former President Pervez Musharraf. One was also convicted of leading a militant siege of Pakistani army headquarters in garrison city of Rawalpindi in 2009.
Local militants have threatened attacks to avenge the hanged men.
Khan, the minister, said Pakistan was at war with the militants. He appealed to the nation to help authorities in a countrywide crackdown on the insurgents.