Pakistani police say a bomb exploded outside a girls' school in the country's volatile northwest, wounding two police officers early on May 8.
"Two counterterrorism department personnel were wounded" in the blast near the city of Peshawar, but no students were harmed as classes had not yet begun, city police chief Muhammad Tahir said.
The bomb went off when a police vehicle drove by, he said, adding that a second device was found nearby but was defused.
Local media published photos of what it described as the main gate of the school damaged by the blast.
There was no immediate claim of responsibility for the attack, but Taliban militants opposed to girls' education have bombed hundreds of schools in the northwest and tribal areas bordering Afghanistan.
Peshawar, the capital of the Khyber Pakhtunkhwa Province, was the site of Pakistan's deadliest ever terrorist attack, a Taliban assault on an army-run school in December 2014 that left more than 150 people dead, most of them children.