More than 1,700 ethnic Karens from Burma have fled into Thailand to escape fighting between government troops and rebels from the Karen National Union (KNU).
It is reportedly the second time in three months that refugees from Lobohe, a village about 2km from the Thai-Burma border, have crossed into Thailand because of clashes in the region.
The KNU has been fighting the Burmese Government for greater autonomy for more than 50 years.
Earlier this month, Thailand asked the international community to help it repatriate over 100,000 Burmese refugees living in camps on the Thai-Burma border.
Reports said the villagers had already fled to Thailand once before, but had crossed back to Burma a month ago when they thought peace had settled in the region.
"We want to stay on Burmese soil. We never intended to spend our life in Thailand," one refugee, Saw Pha, told Associated Press news agency.
"About one month ago we went back to Labohe village. We had set up a new school and clinic. The children had been going to school for about two weeks," Saw Pha said.
"Now the Burmese army have attacked again and we have to escape again."
Thai authorities were not immediately able to confirm the number of villagers who had entered the country this week. Karen community leaders said 1,746 had crossed the border, with few or no possessions.