Pakistani security forces on Wednesday repulsed an attack by militants on a complex outside the strategic port of Gwadar, killing all eight of them, officials said.

China has invested heavily in the mineral-rich southwestern province of Balochistan, including developing Gwadar, despite a decades-long separatist insurgency.

Armed with guns and bombs, the militants stormed the complex just outside the port that houses offices of government departments, intelligence agencies and paramilitary forces, said Saeed Ahmed Umrani, a government commissioner. 

The militants detonated a number of bombs before launching a shooting attack and trying to storm the complex, he said.

In a post on social media platform X, Provincial Chief Minister Sarfraz Bugti said eight militants were "neutralised by security forces", adding: "The message is loud & clear. Whosoever chooses to use violence will see no mercy from the state."

There were reports of at least one soldier killed and others wounded, Umrani said. The army did not give details.

The Baloch Liberation Army (BLA), the most prominent of several separatist groups in Balochistan, claimed responsibility for the assault in a statement, saying its militants attacked Pakistan intelligence agencies' offices.

The BLA has previously been involved in attacks on Pakistani and Chinese interests in the region and elsewhere.

The deep-water port is key to the China-Pakistan Economic Corridor (CPEC) that also encompasses roads and energy projects and is part of Chinese President Xi Jinping's Belt and Road Initiative.

Chinese targets have previously come under attack by several Baloch militant groups in Pakistan, who say they have been fighting for decades for a larger share in the regional wealth of mines and minerals denied by central government in Islamabad.