Two police personnel were killed and 25 others injured after a bus carrying the officers plunged in a ravine in Attock, reported Aaj News on Wednesday.
A rescue operation is underway to help the injured officers.
Initial reports indicate the vehicle's brakes failed, causing the accident. The police officials were on their way to Islamabad ahead of Pakistan-Tehreek-e-Insaf’s (PTI) long march.
The march kicked off on Wednesday after PTI Chairman Imran Khan reached Swabi by helicopter from Peshawar. He has asked supporters and PTI members to converge in Islamabad.
Last month, at least six people were killed and several others wounded when a speeding passenger bus rammed into another passenger bus coming from opposite side on Jhang Layyah road.