A suicide bomber targeted a bus carrying school children in Pakistan's southwestern Balochistan province, killing at least four children, authorities said on Wednesday.  

Two adults — the bus driver and his assistant — also lost their lives in the attack, which took place in the restive province's Khuzdar district.

What do we know about the attack?

The bus was headed to a military-run school at the time of the attack. Around 40 students were in the bus at the time.

Security forces quickly arrived at the scene and cordoned off the area as the victims were taken to nearby hospitals. 

Authorities have launched an investigation into the incident.

"The initial probe suggests it was a suicide bombing," Yasir Iqbal Dashti, a senior local government official in Khuzdar district, told the AFP news agency.

No group has claimed responsibility for the bombing.

What did Pakistani PM and army say?

The Pakistani military has released a statement blaming India for the attack.

Prime Minister Shehbaz Sharif also accused India of involvement, without providing any evidence to support the claim. He vowed to bring the perpetrators to justice.

There was no immediate comment from New Delhi.

Tensions between the two nuclear-armed neighbors are already running high following their recent dayslong military confrontation in which both countries launched missiles and drones on one another .  

Both New Delhi and Islamabad then agreed to a ceasefire.

What's the situation in Balochistan?

Balochistan is the largest province by area in Pakistan, but is sparsely populated by around 9 million Balochs.

The Baloch, a minority Sunni Muslim ethnic group, say they face discrimination and exploitation by the central government.

They point to the community being among the poorest in the country despite Balochistan boasting vast natural mineral resources such as gold, diamonds, silver and copper. 

The province, which borders Afghanistan and Iran, has witnessed a separatist insurgency for decades, with militants often targeting security forces as well as foreign nationals.

The Baloch Liberation Army (BLA) is the most active militant group in the region. It blew up a railway track and took passengers from a train hostage in March, killing 31.

The security situation in the province has worsened this year as several Baloch separatist groups announced the formation of a common armed front in March.

Edited by: Kieran Burke