A search operation was launched Tuesday in the vicinity of the airport in Pakistan's capital city Islamabad and adjacent areas.
The police and Elite Force personnel launched the joint operation in view of the terrorist threat in Rawalpindi and Islamabad, Geo News reported.
During the search, the entrance and exit routes of the Benazir Bhutto International Airport were closed.
At least 12 people were detained Monday and later released after interrogation in the twin cities.