HONG KONG (AP) — Four passenger buses and a truck collided near a Hong Kong road tunnel Friday and about 70 people were injured, including children. Most of the injuries were minor.

The accident occurred after midday near a tunnel entrance on Tseung Kwan O Road in Lam Tin, a residential area in Kowloon. Some 60 people sustained light injuries and around nine others suffered more serious injuries, police said.

It was unclear what caused the collision.

Scores of firefighters, paramedics and police rushed to the scene. Several people lay on stretchers and at least one passenger was seen being helped out of a vehicle. A window on the side of a bus was shattered.

Some of the injured, including elderly people, were treated by paramedics at the scene. A group of primary school students was seen sitting on the road and some of them sustained hand injuries.