The IS group Thursday claimed the killing of two Chinese citizens who were kidnapped last month by armed gunmen in southwestern Pakistan's restive Balochistan province.
The claim was made in a brief Arabic message carried by the group's Amaq news agency. There was no immediate confirmation from Chinese or Pakistan officials.
Hours earlier the Pakistan army issued a statement saying its forces conducted an operation against IS earlier this month, killing up to 15 militants from Lashkar-e-Jhangvi Al-Almi (LeJA) who were in communication with IS about establishing a base in Balochistan.
The two Chinese workers were abducted in Quetta where the pair had been studying Urdu at a language centre, according to a Chinese envoy in the country.
Beijingis ramping up investment in its South Asian neighbour as part of a plan unveiled in 2015 that will link its far-western Xinjiang region to Gwadar port in Balochistan with a series of infrastructure, power and transport upgrades.
Pakistanhas been battling Islamist and nationalist insurgencies in mineral-rich Balochistan since 2004, with hundreds of soldiers and militants killed in the fighting.
Bordering Iran and Afghanistan, it is the largest of Pakistan's four provinces, but the roughly seven million inhabitants have long complained they do not receive a fair share of its gas and mineral wealth.
IS has been making inroads in the country through alliances with local militant outfits, though its presence is generally downplayed by the government.