Three children in Bekasi regency, West Java, suffered severe burns after getting caught in a sand mound suspected of containing oil waste last Thursday.

The sand mound is located on a piece of deserted land in Kramat Blencong, Tarumajaya district.

Dwi Rahajeng said on Monday that her 8-year-old son, Muhamad Ramadan, and his friends Denda, 9, and Raga, 8, were playing on the deserted land last Thursday when they decided to climb the sand mound.

Denda and Raga were the first ones to sink into the sand, followed by Ramadan who had been trying to pull them out.

“The whole area smells like oil; as if oil waste had been dumped there, but I don’t know that for sure,” Dwi said as reported by kompas.com.

The moment the children pulled themselves free from the mount, their skin began to sting, she said.

Denda and Raga were administered to Koja Hospital while Ramadan was taken to the nearest clinic.

Tarumajaya Police chief Adj. Comr. Agus Rohmat said that authorities were currently investigating the matter to discern what had caused the severe reaction.

Investigators have taken samples of the sand mound that are currently being tested, he added.

The scene has been cordoned off with a police line to prevent more people from coming in contact with the sand, according to kompas.com.

In late December last year, residents of Marunda subdistrict, North Jakarta, came across several soil mounds suspected of containing hazardous and toxic waste. Suspicions were raised on its flammable nature after one of the mounds emitted smoke and later caused a fire on Dec. 28. (sau)