Twenty-six Hmong children said to have gone missing from a refugee camp in Thailand have been found in neighbouring Laos, a UN official says.
The children disappeared from a camp in Phetchabun, Thailand
The two countries are now discussing how to re-unite the children with their parents, the official said.
Laos accused Thailand on Thursday of having deported the children.
Thailand has not commented on the charge but says it has the right to deport illegal immigrants such as the Hmong, who arrived there from Laos.
"We cannot allow them to live in Thailand because they broke the law by entering illegally," the Thai army's Maj Gen Wantip Wongwai told Reuters news agency, in an apparent reference to thousands of Hmong migrants in the province of Phetchabun.
"We are not sending them back by force. We are trying to convince them to go home," he told the agency.
Thailand last year asked Laos to take back Phetchabun's 5,000-odd Hmong migrants, who arrived claiming they were being persecuted in Laos.
A spokesman for the UN refugee agency, the UNHCR, said it was not clear how the 26 children from a migrants camp in Phetchabun had ended up in Laos.
HMONG IN LAOS
Ethnic group that often complains of marginalisation in Lao society
Took the side of the US in the Vietnam War - and say they are persecuted because of it
Many still live in jungles
Small numbers say they are fighting rebel insurgency
Thousands have fled to Thailand in recent years
US took in 14,000 Hmong recently, but has no plans for taking more
"It seems they had gone out of the camp in a group and were eventually sent to Laos," spokesman Bhairaja Pandey said.
He said it was important Bangkok and Vientiane re-unite the children with their parents speedily.
"It's children. It's a very sensitive issue. I believe they can find a solution fairly quickly," he said.
Concern had already been voiced for the families of the children, who said they undertook the arduous journey across the border from Laos last year in the belief - proved to be mistaken - that the US was still taking in Hmong from Thai refugee camps.
On Thursday Laotian foreign ministry spokesman Yong Chanthalangsy told the French news agency AFP: "The US embassy informed us that 26 children have been forced by Thai police to cross the border."
"These activities of the Thai police are illegal and are in violation of the existing mechanisms between the two countries," Mr Yong said.
Analysts say the issue highlights the need to clarify the fate of the Hmong refugees still living in Phetchabun.