An attack on Chinese engineers in Pakistan's southwestern province of Balochistan was thwarted by Pakistan's military, leaving two militants dead and the Chinese workers unharmed, police say.

Chakar Baloch, the police superintendent for the district of Gwadar, where the attack took place, told CNN that a clearance operation is underway after clashes between police and militants went on for two hours. Two security personnel were injured.

In a statement to CNN, the Baloch Liberation Army, a militant separatist group, claimed responsibility for the attack.

Pakistan's armed forces said at least two militants were killed and three others were injured in an exchange of fire with security forces.

The military said that security forces have cordoned off the entire area and launched a search operation.

The Chinese Embassy in Pakistan said it strongly condemned the attack and urged the Pakistani authorities to punish the perpetrators and do all it could to prevent further attacks.

"China will continue to work with the Pakistani side, to jointly counter the threats of terrorism and earnestly protect the safety of Chinese personnel, institutions and projects in Pakistan," the statement said.

Bordering Afghanistan and Iran, Balochistan is Pakistan's largest but least populated province. It is fundamental to the country's massive multibillion-dollar infrastructure deal with Beijing, the China-Pakistan Economic Corridor (CPEC).

China is a close partner of Pakistan and its biggest source of military and economic support. But in recent years terrorist attacks targeting Chinese nationals and their interests in Pakistan have alarmed Beijing.

In April 2022, three teachers from China and a driver were killed in a suspected suicide bombing near the University of Karachi's Confucius Institute. The Baloch Liberation Army also claimed responsibility for that attack, saying that it targeted the Confucius Institute because it is a "symbol of Chinese economic, cultural and political expansionism."

Meanwhile, the last major attack on Chinese engineers was in July 2021 in the north of Pakistan. More than a dozen people were killed after a bus carrying Chinese engineers fell into a ditch following a "fiery explosion," according to local police.