The police received reports of the six-vehicle pile-up at 12.57 am, while firefighters and paramedics were dispatched to the scene immediately.

The Fire Services Department said at least 75 people were injured, including four who sustained severe injuries. Among the injured were 50 students and 20 elderlies and they were brought to the city’s hospitals for treatment.

It was said the students were heading back to campus after a school trip when the accident happened.

Police were still investigating the cause of the accident.

In view of the traffic accident, the Transport Department said all lanes of Tseung Kwan O Road (Tseung Kwan O bound) near Tsui Ping South Estate are closed to all traffic.

“Motorists are advised to use alternative routes such as the Tseung Lam Lam Tin Tunnel as traffic is congested now,” it wrote.