Pakistan has arrested more than 5,000 suspects since the Lahore bombing on Sunday, a provincial minister said yesterday.
Most of them have been released but 216 suspects are still in custody, said Punjab minister Rana Sanaullah.
Security forces have moved rapidly in response to the bombing, claimed by the Taliban, that killed at least 72 people and injured hundreds more. Military and government officials on Monday said that the army was preparing to launch a new paramilitary counter-terrorism crackdown in Punjab, as it did more than two years ago in the violent southern megacity of Karachi.
Sanaullah said at least 160 raids have been carried out since Sunday night by police, counter-terrorism and intelligence agents. He confirmed that army and paramilitary forces would be used in future operations.
The bombing was targeted at Christians but it is believed more Muslims than Christians died. Many of the victims were children.
The Taliban faction responsible for the bombing, Jamaat-ur-Ahrar, warned Pakistani media they could be the next target.
"Everyone will get their turn in this war, especially the slave Pakistani media," Ehsanullah Ehsan, spokesman for the group, tweeted. "We are just waiting for the appropriate time."
The Lahore attack is the latest in a series targeting Christians, who are feeling increasingly vulnerable in a climate of rising fundamentalism and extremism.
The Christian community is calling on the government of Muslim-majority Pakistan to do more to protect them.
Last March, suicide bombers struck two Lahore churches, Christ Church and another close by, killing at least 14 people. In 2013, a pair of suicide bombers blew themselves up outside the 130-year-old All Saints church in Peshawar after Sunday mass, killing at least 78 people.
Now the Easter attack by Jamaat-ur-Ahrar, which once swore support for Islamic State, has fueled worries that militants in Pakistan are increasingly subscribing to the IS brand of ultra-sectarian violence against those perceived as infidels.
"Terrorists didn't used to be so focused on our community. Now all their attention is on us," said Rev Irshad Ashnaz, the vicar of Christ Church. "Perhaps it's time for the government to turn their attention toward us also."
He added: "These people are roaming around freely and no one is stopping them."
Demonstrators demanding martyrdom status for Mumtaz Qadri, executed for the murder of Punjab governor Salman Taseer, are continuing their protest in the capital Islamabad. They are calling for the immediate execution of hundreds of people in jail on blasphemy charges.