GUIYANG - Five street children who were found dead inside a dumpster in southwest China have been confirmed being poisoned by carbon monoxide, local authorities said on Sunday.

The autopsy results showed that the boys, all aged about 10, died from carbon monoxide poisoning, and the possibility of instrumental injuries or mechanical asphyxia has been ruled out, according to sources with the publicity department of Communist Party of China Bijie city committee in Guizhou Province.

Leftover of burnt charcoal was found inside the dumpster, indicating that the boys might be burning charcoal for heat before they died, the sources said.

The bodies of the children were found by a trash collector in a dumpster along Huandong road in Qixingguan district, Bijie City, on Friday morning, according to a report by the Beijing News.

Unidentified photos uploaded by netizens onto the Internet showed that the dumpster is about 1.5 meters long, 1.3 meters wide, and the lid could be airtight.

Local security authorities have identified three of the victims, all from the district of Qixingguan, while the identity confirmation of the other two is under way, the sources said.

Bijie is a mountainous city located in northwest Guizhou, some 200 km away from the provincial capital of Guiyang. It drizzled Friday night and the low temperature hit six degrees Celsius, according to the local weather report.

A further investigation into the case is under way.

The incident has triggered widespread uproar on the Internet, and the post on the popular Sina Weibo, a Twitter-like microblogging service, has topped the most-viewed topics of the day, with hitting exceeding 2.5 million as of 8 p.m. Sunday.

While some Internet users accused the local government of its negligence, others said the parents of these children are also to blame for their lack of responsibility in looking after the kids.

"Both the government and the families of the children should take the blame for the tragedy," said Sina Weibo user with the screen name "Fanxin Wudi".

"In reminded me of The Little Match Girl by Hans Christian Andersen. Isn't it that such things only happen in fairy tales?" another user, "Saludika", said.

"What a cold world this must be for the five children!" "Lu_ Yao", another user, said.