China said on Friday it was "gravely concerned" at Islamic State claims that the group killed two Chinese teachers it kidnapped in Pakistan's Baluchistan province last month.
China said it was working to verify the claim.
Armed men pretending to be policemen kidnapped the two language teachers in Quetta, the capital of the southwestern province, on May 24.
The killing of the teachers was claimed by Islamic State's Amaq news agency on Thursday.
"Islamic State fighters killed two Chinese people they had been holding in Baluchistan province, southwest Pakistan," Amaq said.
A Baluchistan government spokesman said officials were in the process of confirming whether the report was correct.
China's Foreign Ministry expressed grave concern.
"We have been trying to rescue the two kidnapped hostages over the past days. The Chinese side is working to learn about and verify relevant information through various channels, including working with Pakistani authorities," the ministry said in a short statement.
"The Chinese side is firmly opposed to the acts of kidnapping civilians in any form, as well as terrorism and extreme violence in any form," it said.
There was no immediate comment from Pakistan's interior ministry or its foreign office.
China said on Friday it was "gravely concerned" at Islamic State claims that the group killed two Chinese teachers it kidnapped in Pakistan's Baluchistan province last month.
