“A police van was on patrol when a remote-controlled IED (improvised explosive device) exploded,” Warsak Superintendent of Police (SP) Arshad Khan told Dawn.com.

“Four to five kilogrammes of explosives were used in the blast,” SP Arshad said.

He said six to seven people have been detained for probe.

Senior Superintendent of Police (SSP) Operations Kashif Zulfiqar told Dawn.com that evidence has been collected from the crime scene.

“There has been an increase in terrorist attacks on Warsak Road,” SSP Zulfiqar said. “A few days ago, a grenade was thrown at the Mathura police station.”