Islamabad, Pakistan (CNN) -- Four children were hurt in a bomb blast in southwest Pakistan on Tuesday, officials said.

The blast took place in the town of Turbat in Balochistan province, said Tariq Qamar, Turbat's district commissioner.

Most of the injuries were minor, although one child lost part of his hand, the commissioner said.

Authorities could not immediately say whether the bomb was planted on a bus that the children were riding in, or whether the bus rode over one.

Balochistan, located near the Afghan border, is the largest province in Pakistan but one of its least populated. The province is rich in natural resources.

Militants there have for years complained that the central government has paid little attention to them and their economic needs. They have been fighting Pakistani military forces for self-rule.

More recently, the province has seen an influx of Afghan refugees. And the Afghan government believes that key Taliban leaders may be hiding among them.

Pakistan has said the militants in Balochistan do not have links to the Islamic hard-liners who have launched assaults in other parts of the country.

Soon after the ruling Pakistan Peoples Party swept into power, it called for an end to military operations in Balochistan, the largest of Pakistan's four provinces.

It said it would work toward giving "maximum provincial autonomy" to the area.