Police have begun a further investigation into Monday's fatal explosion at a gambling den in Kaili, Southwest China's Guizhou province.

Fifteen people were killed in the blast, which occurred at 2:40 pm at the gambling den on a remote mountain slope in Kaili's Laoshan Village, police said.

Eight people were injured. As of Tuesday afternoon, they were all in stable condition.

The casualties were people who had gathered at the site to gamble, police said. Police and rescue staff are collecting evidence and identifying the bodies.

The eight people injured are being treated at two hospitals in Kaili, and one may have lost his eyesight. Five are receiving treatment at the Qiandongnan Prefecture People's Hospital for injuries to their faces and heads, said Jiang Xiaohai, a doctor at the hospital.

"My husband called and said he was dying and had been blinded. He said, 'I have only my last breath', and he asked me to take care of our child," said Pan Shasha, the wife of a 26-year-old survivor who sustained injuries to both of his eyes in the blast.

Pan said she went to the blast site immediately after receiving the call. She found her husband with blood on his face, and other bodies nearby.

"I heard that they were playing the Gundilong gambling game in the den," she added.

Gundilong is played using a big box and dice. Gambling games have been found in remote areas in Guizhou and some other regions in China.

According to a villager who wished to remain anonymous, the gambling den was set up in the first half of last year and was generally frequented by out-of-towners who had driven to the site.

"They used to gamble at a neighboring village, but they moved here several months ago. I heard that their bets were big," she said.

Some local villagers told Xinhua that there were often many cars gathered near the gambling den with up to two dozen people inside. Police have detained eight suspects.

A working team from the Ministry of Public Security arrived at the scene early on Tuesday to help with the police investigation.