Six teams of sniffer dogs, armed personnel carriers, bomb disposal squads and commandos participated in the operations, carried out across Islamabad in the light of intelligence inputs about militant threats, Dawn reported.
The swoops, carried out by the police, Pakistan Rangers, and intelligence agencies Saturday, also led to the recovery of arms and ammunition.
"These were intelligence-based operations conducted in view of the fresh threats from militants after the execution of two convicted terrorists," a police official said, adding that these operations will continue for a few more days.
Besides, Afghan settlements, bus terminals and under-construction buildings were also searched in the city for terrorists.
"We have received a number of threats following the government's decision to end moratorium on the death penalty," the official added.
Most of the alerts coming from intelligence and security agencies are on educational institutions, installations of the armed forces and foreign diplomats and missions.