Updated

China will investigate claims that two of its citizens were engaged in illegal preaching before they were killed by Islamic extremists in Pakistan, a government spokesman said Wednesday.

The two Chinese citizens were abducted at gunpoint on May 24 in the city of Quetta. Islamic State militants claimed the killings on Friday and sent local journalists a video purporting to show their bodies.

Chinese officials have yet to directly confirm the deaths, Chinese foreign ministry spokesman Lu Kang said in a statement. China's government "will continue to make the greatest efforts to work with the Pakistani side on coming to a speedy clarification of the relevant issues," he said.

Pakistani officials identified the victims as Lee Zing Yang, 24, and Meng Li Si, 26.

Pakistan Interior Minister Chaudhry Nisar Ali Khan said they had entered the country on business visas but later began "preaching." He did not offer further details but called for a review of Pakistan's visa policies with regard to Chinese nationals.

During the abduction, gunmen dressed as police stopped a car carrying Lee and Meng and shot and wounded a man who intervened after he rescued a third person from the car, according to Pakistani police.

The police said at the time that Lee and Meng had been teaching at a private language school.

China, a longtime ally of Pakistan, is investing billions of dollars in an economic corridor linking the Asian neighbors. Thousands of Chinese nationals work in Pakistan and have occasionally been targeted in attacks by anti-government militants.