Hangzhou City, Zhejiang Province, east China - July 17, 2017
1. Surveillance footage showing truck-semitrailor collision, explosion
2. Various of firefighters putting out fire
3. SOUNDBITE (Chinese) Zhang, truck driver:
"The explosion went off just at the collision. I didn't even see how it happened. I just heard a big boom and it had occurred."
4. Various of firefighters putting out fire
5. Various of firefighters dismantling truck
6. Picture of paint in truck

A violent explosion went off when a van hit a parked semi-trailer on an expressway near Hangzhou of east China's Zhejiang Province early on Monday. Nobody got hurt in the incident while police are investigating into the cause of the blast.

Surveillance footage showed the van taking a bend but it brushed onto the semi-trailer parked on the shoulder of the expressway .

"The explosion went off just at the collision. I didn't even see how it happened. I just heard a big boom and it had occurred," said the van driver surnamed Zhang.

The expressway had to be closed down while firefighters were fighting the chemical fire on the van. Police video showed burned residues of paints and their containers on the van.

It took one hour and a half to reopen one lane to traffic along that expressway.

Initial inquiries showed that the semi-trailer was carrying steel products while the van was carrying paper and paints.

Samples of the paint were sent for laboratory investigation.