Pakistan has deployed a 15,000-strong military force to protect Chinese nationals working on energy and infrastructure projects in the country, President Mamnoon Hussain said on Sunday, after the abduction of a Chinese couple raised safety concerns.

The president told visiting Chinese Foreign Minister Wang Yi in Islamabad that the protection of Chinese citizens working in Pakistan was the “top priority” of the government, read a statement issued by the presidency.

Beijing is investing around $50 billion in its South Asian neighbour as part of a plan unveiled in 2015 to link its far-western Xinjiang region to Gwadar port in Balochistan with a series of infrastructure, power and transport upgrades.

But fears over safety arose last month when two Chinese workers were abducted in Quetta, Balochistan, which is at the heart of the China Pakistan Economic Corridor (CPEC) project but racked by separatist and religious insurgencies.

Authorities were going to all possible efforts to arrest those responsible for kidnapping, Hussain said.

China has stated it will cooperate with Pakistani authorities to investigate whether the two Chinese citizens — who were allegedly killed by the Islamic State group in the country — had been illegally preaching. So far there has been no official confirmation of the Chinese pair's fate.

Later in the day, Chinese Foreign Minister Wang Yi and his delegation also called on Army Chief General Qamar Javed Bajwa and discussed matters of mutual interest and regional security with special reference to Afghan situation and CPEC came under discussion.