China investigates IS claim that two citizens were killed in Pakistan
Officials are investigating claims by Islamic State that two Chinese teachers abducted in Pakistan have been killed.
A 24-second video appearing to show the bodies of a Chinese man and woman was sent to journalists working in the south-western province of Baluchistan, apparently by the Islamic State group.
Pakistan officials said they were aware of the video, but the bodies had not been found or their identities verified.
"According to the initial information from relevant departments of Pakistan, the two Chinese citizens kidnapped may have been unfortunately killed," said Chinese Foreign Ministry spokeswoman Hua Chunying.
"We are highly concerned about that and will try our best to get more information on that through various approaches."
The IS claim came hours after Pakistan's military released the pictures of what it said were 12 slain members of the militant group.
They were killed in this week's operation in Baluchistan, where the military said it foiled an attempt to set up an organised IS militant base.
Ms Hua said that after learning the two were missing, the Chinese government and diplomatic missions in Pakistan immediately activated their emergency response mechanism and coordinated with the Pakistani side to "rescue them with our utmost efforts".
Ms Hua gave no details about the two, other than that they were not a couple and came from different provinces in China.
The two teachers at a private language school were kidnapped on May 24 by gunmen dressed as police who stopped their car in Quetta, the capital of Baluchistan.
A bystander who attempted to intervene was shot and wounded while rescuing a third person.
A statement late on Thursday from the IS news agency said the two Chinese teachers had been killed.
Thousands of Chinese work in Pakistan and have sometimes been targeted by militants.
China is a long-time ally of Pakistan and is building roads and power plants under multibillion-dollar project termed the China-Pakistan Economic Corridor.
Islamic militants opposed to Chinese rule in the north-western region of Xinjiang are also believed to be sheltering in Pakistan's lawless tribal areas, from which they have threatened to launch attacks.
Ms Hua said the abductions would have no effect on Chinese-Pakistan relations or plans for development projects.
"Pakistan always pays great attention to the protection of Chinese citizens and institutions there and has made great efforts in this regard. Since this abduction took place, China and Pakistan have been in close communication," Ms Hua said.
She praised Pakistan for "sparing no effort to investigate the incident and search and rescue the hostages".