Gunmen assault a school vehicle in Punjab, Pakistan, killing two children.

Gunmen opened fire on a school bus in Pakistan’s eastern Punjab province, killing two children, police said.

Five children were wounded in the attack which took place in a village in the district of Attock on Thursday morning as the children were travelling to school.

Police said the assailants appeared to be targeting the driver, who was also wounded.

Local officials and media reports said that the children were as young as five.

“Our initial investigations indicate that the driver had an enmity with someone,” Mohammad Shakil, a local police official, told The Associated Press news agency.

Preliminary investigations on the motive for the attack pointed towards a feud between two families, said Usman Haider, another police official, who spoke to Germany’s DPA news agency.

However, police were also “looking into the possibility of terrorism”, he added.

Pakistan’s President Asif Ali Zardari and Interior Minister Mohsin Naqvi denounced the attack and ordered the best possible medical treatment to be provided to the wounded.

Attock district is not far from Pakistan’s restive northwest, where attacks by armed groups have surged in recent years.

In 2014, Taliban gunmen killed nearly 150 children in an attack at a military-run school in northwestern Pakistan.