Burma's military junta has asked the Thai Government to launch an inquiry into the deaths of 13 Burmese nationals whose bodies were found dumped in north-eastern Thailand.

Police in Prachinburi province initially said they believed the Burmese - who included children and teenagers - had been murdered.

But a forensic investigation has found they suffocated, probably accidentally during the difficult journey from Burma.

Officials in Thailand say they believe the Burmese were the victims of an illegal smuggling racket.

A police spokesman, Major General Pongsapat Pongjaroen, told the BBC it was possible the victims had suffocated as they crossed the border underneath a truck.

The bodies, in empty sandbags, were found dumped at a quarry and hidden under piles of fertiliser sacks.

Migrant workers

The head of the police forensic department, Major General Chid Samathiwat, said he estimated the victims were aged between 12 and 25 years old and that they died late on Monday night.

He said the victims' heads were twisted due to rigor mortis, and that their necks were not broken as was previously thought.

Thailand has just begun a campaign to repatriate thousands of Burmese working illegally in the country. Burma has set up a camp at Myawaddy, on the Thai-Burma border to receive them.

Before the forensic findings emerged, Kyaw Win, Burma's deputy chief of military intelligence told reporters he believed the 13 Burmese had been murdered.

"This is something that should not have taken place at all at a time when we are repatriating," he said.

"We will make a request through the foreign ministry to the Thai Government to take serious action against the murderers after investigation and to prevent similar incidents from breaking out and to give Burmese workers protection."

The Burmese workers in Thailand are known to be unpopular with the local population.

Last month the bodies of about 14 workers, thought to be Burmese, were found dumped in a creek in north-western Thailand.

Officials said they suspected those victims were Karen migrant labourers killed by their Thai employer to avoid paying them, or hired for criminal activity and then killed when they had finished the job.