A bomb struck a bus carrying children to an army-run school in south-western Pakistan on Wednesday, killing five people, including three children, and injuring dozens more, officials said.
The blast targeted the vehicle in the city of Khuzdar, in the restive province of Balochistan, as it took students to class, said local official Yasir Dashti.
Three children and two adults were among the dead, an army statement said. Health officials feared the death toll could rise, as many of the 38 wounded children were in a critical condition.
The Baloch Liberation Army (BLA), a rebel group fighting for the independence of the region from Pakistan, claimed it targeted the bus, but said it was transporting the soldiers.
The violence orchestrated by sub-nationalist rebels has surged in Balochistan, a region that borders both Afghanistan and Iran, and is a hub of Chinese investment and connectivity projects.
Dozen of people were killed in March when BLA militants hijacked a bus carrying the soldiers and their families during the Muslim holiday of Eid al-Fitr.