HANGZHOU, CHINA (CBSDFW.COM) — 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 was hurt in the incident.  Police are investigating into the cause of the blast.

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

READ MORE: 'A Step Towards Healing And Normalcy' Colleyville Synagogue Holds Services A Week After Hostage Standoff

“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 named Zhang.

The expressway had to be closed down while firefighters put out the chemical fire on the van. Police video showed burned residue of paint and other containers on the van.

READ MORE: McPherson FG As Time Expires Lifts Bengals Past Titans 19-16

It took one and a half hours 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.

MORE NEWS: TCU Stuns No. 15 Iowa State 59-44

Samples of the paint were sent for laboratory investigation.