The Foreign Office on Monday said that it has been confirmed through DNA testing that two Chinese nationals, who had been kidnapped from Balochistan earlier this year, have been killed.

According to a statement issued by the FO, the Chinese couple Lee Zing Yang, 24, and Meng Li Si, 26, had been killed in June ─ a month after they were kidnapped from the Jinnah Town area of Quetta on May 24.

The Foreign Office vowed that the government would "continue to conduct a thorough investigation and apprehend the perpetrators of this crime and to bring them to justice".

The confirmation from the Foreign Office comes months after the militant Islamic State (IS) group claimed it had killed the Chinese man and woman, who had reportedly been 'preaching' in Balochistan under the garb of learning Urdu.

"The Government of Pakistan expresses its deep sense of shock and grief on this brutal act of terrorism," the FO's statement read. The government also extended its condolences to Beijing and to the Chinese couple's relatives.

In June, the interior minister was informed that the Chinese were involved in preaching instead of business activities — their declared purpose for visiting Pakistan.

It was not clear what the interior ministry suspected them of 'preaching'. The interior ministry had also confirmed the two Chinese had been killed but it was not clear if their bodies have been found.

The then interior minister Chaudhry Nisar Ali Khan had ordered an initial review, followed by regulation and the streamlining of the visa process to avoid the misuse of business visas by foreign nationals.