At least four children were killed by a suicide bomber who targeted an army school bus in Pakistan's restive Balochistan province, a government official said on Wednesday.
"The bus was on its way to a school in an army cantonment," said Yasir Iqbal, the administrator of Khuzdar district, where the incident took place.
Around 40 students were in the bus that was headed to the army-run school, Iqbal said, adding that several were injured in the incident.
Balochistan is Pakistan's largest province by area, but smallest by population. The province of some 15 million people in the southwest of the country is home to key mining projects but has been roiled by a decades-old insurgency.
This militant attack is reminiscent of one in Pshawar in 2014
No group immediately claimed responsibility for the blast, which was reminiscent of one of the deadliest militant attacks in Pakistan's history when an attack on a military school in the northern city of Peshawar in 2014 killed more than 130 children.
It was claimed by the Tehrik-e-Taliban Pakistan (TTP), an ultra-radial Islamist group.
Attacks by separatist groups in Balochistan have risen in recent years. The Baloch Liberation Army, a separatist militant group, blew up a railway track and took passengers from a train hostage in March, killing 31.