Thirteen people were wounded when a gas tanker truck exploded in northwestern Cambodia’s Siem Reap province, a deputy provincial police chief confirmed on Thursday.

The incident happened at a liquefied petroleum gas station on Wednesday afternoon at Wat Bo village in Siem Reap provincial town, when the 2,000-liter-LPG tanker truck was transferring the gas from the tanker truck to the station’s storage tank.

“A total of 13 people, including an intervention police officer and two female westerners, got wounded in the blast,” Brigadier General Phing Sambath, deputy police chief of Siem Reap province, told Xinhua, adding that six of them were seriously injured.

The two westerners, who got burns on their skins, were the passers-by when the tank exploded, he said, adding that firefighters took about one hour to extinguish the blaze.

According to Sambath, the cause of the explosion is unknown yet, and an investigation is underway.