According to Bukit Aman Traffic Enforcement Investigation Department Assistant Superintendent ASP Hazil Reza Mohd Ghazali, the 3pm incident, which was captured on video, was caused by brake failure.

Police however are also investigating whether the bus driver was drowsy when the incident occurred.

Hazil also told the Malay daily that all 23 passengers on the bus escaped unscathed.

Meanwhile, The Star quoted Perak traffic police chief Supt Wan Jamil Wan Chik as stating that traffic was already heavy on the particular stretch when the bus came around a curve on the highway and attempted to squeeze between two cars.

“The bus then rammed into the right side of one of the cars before hitting the left side of the other car.

“The bus did not stop and rammed into a third car in front, causing seven more cars to crash into one another,” the daily reported him as saying.

The bus driver has since been detained for further investigations.