BEIJING: China has asked Pakistan to punish the perpetrators of a bus attack that killed at least 10 people including Chinese nationals on Wednesday, the foreign ministry said.

Beijing condemned the blast, expressed condolences and asked Pakistan to protect the safety of Chinese personnel, institutions and projects, foreign ministry spokesman Zhao Lijian told a regular news briefing.

Bus blast near Dasu project kills at least 13, including 9 Chinese

"China has asked Pakistan to thoroughly investigate the truth, hold the perpetrators accountable and give them severe punishment," he said.

At least 13 people, including nine Chinese nationals and two Pakistani soldiers, were martyred after a blast sent a bus plunging into a ravine in a remote region of northern Pakistan on Wednesday, multiple sources told Reuters.

It was not immediately clear whether the blast was the result of a roadside device or something planted inside the bus.

The Chinese embassy in Pakistan said in a statement that nine Chinese were killed.

Inspector General Moazzam Jah Ansari, the top police official of Khyber-Paktunkhwa, the province where the incident occurred, said two soldiers and two locals were also among the dead. Several people were injured.

Foreign Office expresses condolences over lives of Pakistanis, Chinese workers lost in bus accident

"The bus plunged into a deep ravine after the blast and caused heavy losses. The rescue operation is launched and the entire government machinery has been mobilised to rescue the injured by air ambulance," a senior government official told Reuters on condition of anonymity.

Pakistan's Foreign Office also expressed its condolences to the families of the Chinese and Pakistani workers who lost their lives in the bus blast on Wednesday, saying that authorities are providing all possible assistance to the injured and investigations into ascertaining the cause of the incident are underway.