The Ministry of Foreign Affairs (MoFA) said the bus plunged into a ravine "after a mechanical failure, resulting in leakage of gas that caused a blast", reports Geo News.

"Further investigations are underway," read the foreign affairs ministry's statement.

The ministry disclosed that Chinese workers and accompanying Pakistani staff were proceeding to their work place for an ongoing project. It said that local authorities are providing all the support to the injured, Geo News reported.

"The Ministry of Foreign Affairs is closely in contact with the Chinese Embassy for coordination and facilitation," said the MoFA.

Several people were injured in the incident.