ISLAMABAD, Pakistan (CNN) -- Two people were killed when a roadside bomb went off near a police bus carrying prisoners Saturday in northwest Pakistan, an official said.
One of the dead was an officer, according to Dilawar Bangish, police chief of the Kohat District.
Eighteen people, including 16 officers, were injured in the attack in the town of Kohat, Bangish said.
The bus was taking prisoners from the city of Kohat to a jail about 3 miles away, Bangish said.
Kohat is in North West Frontier Province, where dozens of people have been killed by militants this month.
In other violence, Pakistani military airstrikes in Makin killed 15 suspected militants and a civilian female, said Hamidullah Khan, a South Waziristan official.
This bombings hit a high school and four other buildings, Khan said.
The Pakistani military did not confirm the airstrikes.
Makin is close to the border with North Waziristan, part of the Federally Administered Tribal Area. It is about 43 miles southwest of Bannu in Bannu district.
The airstrikes come as Pakistan's military stepped up its Taliban offensive in the Bannu district of North West Frontier Province, which a military spokesman said is a notorious hideout for militants.
The military on Thursday dropped leaflets over parts of Bannu district, warning civilians to leave.
The Bannu offensive has killed 34 suspected terrorists and three more were captured, the military said Thursday.
CNN's Ingrid Formanek contributed to this report.