Prime Minister Imran Khan on Friday assured his Chinese counterpart Li Keqiang that no effort would be spared to fully investigate the bus blast that killed nine Chinese nationals, stressing that ''hostile forces'' would not be allowed to harm the "brotherly" ties between the two countries.

Khan held a telephone conversation with the Chinese premier to express condolences over the loss of lives of Chinese nationals caused by the tragic incident in the Dasu area of the Upper Kohistan district of the restive Khyber Pakhtunkhwa province on Wednesday.

At least 13 people, including nine Chinese nationals and two Frontier Corps soldiers, died and 39 others were injured when the bus carrying Chinese engineers and workers to the site of the under-construction Dasu Dam exploded. The bus fell into a deep ravine after the explosion.

According to an official statement, Khan reiterated that Pakistan and China had an iron-clad friendship that had withstood the vicissitudes of time.

"No hostile forces would be allowed to damage brotherly relations between Pakistan and China,'' he said.

Khan assured Li that no effort would be spared to fully investigate the incident, adding that the security of the Chinese nationals, workers, projects, and institutions in Pakistan was the highest priority of the government.

He also said that the people of Pakistan shared the grief and pain of the bereaved families and underlined that Pakistan was providing the best possible medical care to the injured Chinese nationals.

So far, it is not clear if the blast was caused by a technical failure or the vehicle was hit by an explosion. While China termed the mishap as a bomb attack, Pakistan stated that the blast was caused by a gas leak.

China on Thursday said it is rushing a special team of experts to Pakistan to probe the blast.

The Chinese engineers and construction workers are helping Pakistan build a dam, which is part of the USD 60 billion China-Pakistan Economic Corridor (CPEC).

Meanwhile, The Express Tribune reported that the meeting of the Joint Cooperation Committee – the strategic brain of the China-Pakistan Economic Corridor – was abruptly postponed on Thursday.

The meeting was scheduled for Friday.

The decision to postpone the meeting was taken a day after the Dasu incident, underscoring the challenges that both nations have to face due to changing regional security situation.

China was expected to raise the issue of re-energizing the CPEC, making the CPEC Long-Term Plan 2017-30 effective and issues being faced by Chinese companies working on the CPEC projects, including a delay in clearing their power generation dues.

"The JCC-10 meeting on CPEC which was scheduled to be held on July 16, 2021, has been postponed to a later date after Eid," Lt. General Asim Saleem Bajwa, chairman of the CPEC Authority, tweeted.

He said that a fresh date will be shared when finalized but in the meanwhile, preparations continue.

Bajwa on Thursday received a call about the postponement of the meeting in the midst of a meeting that Planning Minister Asad Umar was holding with the provinces to sort out issues before the JCC, a senior official told The Express Tribune.

He said that the Chinese were not happy with the way Pakistan handled the bus attack issue.

The provision of security to the Chinese nationals and the CPEC assets was also included in the agenda of the 10th JCC meeting. The draft minutes of the JCC suggested that the Chinese were concerned that "changes in regional security situation further the security threats facing CPEC".

The JCC meeting had been scheduled after a gap of 20 months. The last JCC meeting was held in November of 2019.

Planning Minister Umar and China's National Development and Reforms Commission Vice Chairman Ning Jizhe were set to co-chair the all-important meeting that could have given a serious push to the stalled CPEC.