Eight people were killed and 40 injured after a street vendor’s cooking gas container exploded on Saturday night during carnival celebrations in Bolivia’s Oruro city, Reuters reported. Three of those killed were children.

Many of the injured were airlifted to Bolivia’s Capital, La Paz, as local hospitals struggled to cope, BBC reported.

The vendor is believed to have dripped hot oil on the hose of the cooking gas container, which led to the explosion, the city police chief Romel Raña was quoted as saying.

In a post on Twitter, President Evo Morales said he was dismayed at the news.

The incident took place on a crowded street close to the main route of the festival’s parade. Hundreds of thousands of people participate every year in Oruro’s carnival. The city’s carnival, which dates back over 200 years, has been classified as a cultural heritage event by the United Nations.

Besides the explosion, 13 people were killed in traffic and bus accidents in the city as the carnival began on Friday, AFP reported.