New Delhi: The incident of a blast on a bus in north Pakistan which killed 13 people including two Pakistani soldiers and nine Chinese nationals on July 14 has led to war of words between the Pakistani and the Chinese governments.

Intelligence sources said Pakistan officials have been trying to cover up this incident as an accident, saying that this was not a terror attack but a result of the bus falling into a ravine due to a technical fault.

Pakistani officials have tried to produce pictures indicating flaws in the mechanical system of the bus which led to the bus going down the ravine. Even a technical report was produced by them to portray the incident as result of a mechanical flaw.

However, Chinese officials contested this theory from the beginning with the Chinese Embassy insisting that the incident was a suicide attack. According to them, the attacker fired several shots on the bus and used hand grenades before detonating himself. Pakistan has been trying to give the impression that the incident had nothing to do with the overall security situation in Khyber-Pakhtunwa area.

Sources said the Chinese Embassy in Pakistan confirmed death of 9 nationals in an explosion in the bomb attack stating that "Chinese engineers and Pakistan's construction workers have for several years been working on hydroelectric projects as part of the BRI in Khyber-Pakhtunkhwa, where the blast occurred, and the matter was of serious concern to the Chinese".

The Chinese have privately expressed fear of more attacks on CPEC projects in future. They also fear kidnapping of workers of Chinese-owned cellular operator Zong in Pakistan. Zong officials have received threats from time to time.