At least 25 explosive laden vehicles have reportedly sneaked into major cities of Pakistan, following which intelligence agencies have launched a massive search operation.

According to sources, intelligence authorities have issued a warning to all four provinces in this regard, and asked them to take every precautionary measure.

The Interior Ministry has also issued a circular stating that suicide bombers along with the vehicles have entered Peshawar, Lahore, Rawalpindi, Islamabad, Quetta and Karachi, 'The Daily Times' reported.

A private television channel, giving the description about the vehicles, said that the explosive laden vehicles included a Shehzore pick-up van, an ambulance, a blue Pajero and seven Toyota Corollas besides other vehicles.

Meanwhile, Peshawar police has seized three explosive laden vehicles from Budhbeer and Lakki Marwat area of the city.

Following the seizure, security forces have beefed up security across the province and are maintaining a tight vigil on all vehicles entering or leaving Peshawar.