A suicide bombing killed at least 10 people outside the headquarters of a paramilitary force in the southwestern Pakistani city of Quetta on Tuesday, officials said.

Several gunmen stormed the headquarters after the bombing, triggering a gun battle with the paramilitary, provincial Chief Minister Sarfraz Bugti said in televised remarks.

"These cowardly attacks cannot deter us from bringing development and prosperity to our people," he said.

Ten people, including civilians and soldiers, were killed by the attackers, provincial Health Minister Bakht Kakar told Reuters. Another 33 were injured, he said.

Paramilitary soldiers were among those killed but their exact number was not yet known, he added.

Quetta is the capital of restive Balochistan province, which borders Afghanistan and Iran.

The mineral-rich region is home to Gwadar Port, built by China as part of the China-Pakistan Economic Corridor, a $65 billion investment in President Xi Jinping's Belt and Road Initiative, which seeks to expand China's global reach by road, rail and sea.

Both Islamist militants and separatist insurgents, who operate in the region, have stepped up their attacks in recent months.

No group has claimed responsibility for the bombing.

The separatists, who mostly target Pakistani security forces and the Chinese nationals or their projects, say they have been fighting for their due share of regional resources.

The Islamist militants have been fighting to overthrow the government and replace it with their strict Islamic system of governance.

Islamabad alleges that the militant groups are backed by arch-rival India to stoke violence in the region where Pakistan is seeking international investments in mines and minerals, a charge New Delhi denies.