According to Kyodo News Agency, none of the victims have life-threatening injuries following the collision on the Chuo Expressway in Hachioji, a city in the western part of the Greater Tokyo metropolitan area.

Hong Kong’s Dimsum Daily reported that the buses, which were part of the same tour group, carried passengers from Hong Kong, Malaysia, Singapore and Taiwan.

Police said the accident occurred when one of the buses rear-ended the other. They had departed earlier from JR Tokyo station and were on their way to Lake Kawaguchi in neighbouring Yamanashi prefecture.

It is believed the buses kept starting and stopping due to traffic, and the accident occurred when the driver of the second bus failed to notice that the one in front had braked, according to police.

The accident led to the temporary closure of the outbound lanes between Hachioji Junction and Sagamiko Interchange.