Chinese foreign ministry was shocked by the incident in Pakistan and called it an attack on Chinese citizens in which 13 people were killed among them nine Chinese.

Spokesman of china’s foreign ministry Zhao Lijian has asked Pakistan to go into the depth of the issue.

Officials in northwestern Pakistan said that the bus carrying Pakistani and Chinese construction workers fell into a ravine on Wednesday which killed at least 13 people.

Authorities in Pakistan though said that the alleged incident is under investigation but the Chinese embassy based in Islamabad said that the bus was attacked.

Assistant commissioner in Kohistan of Pakistan said authorities believe the incident was an accident but investigations over alleged explosives in the bus are underway.

The cause of the incident is not yet clarified but state officials in Khyber Pakhtunkhwa said it will soon be briefed to the media.

Chinese engineers are working along with Pakistani workers on building a hydroelectric dam in eastern Pakistan, Kohistan.

China is the biggest economic ally of Pakistan which has implemented major economic projects including China-Pakistan CPEC.