Refugees are pouring across Burma’s border into Thailand after heavy fighting erupted this morning in Myawaddy.

Estimates of the number of people fleeing vary – the UN has put the figure at 1000, while eye-witnesses say it is closer to 5,000.

Around 400 people have sought refuge in a monastery in Mae Sot close to the Thailand-Burma Friendship Bridge. A source on the border said that more people were crossing at unofficial border checkpoints close to Myawaddy.

It comes a day after Burma held its first elections in 20 years. Aid groups had predicted that the Burmese junta would step up attacks on rebel groups along the border, but it’s unlikely anyone had foreseen how quickly violence would erupt.

Fighting began early this morning after troops from a breakaway faction of the Democratic Karen Buddhist Army (DKBA) yesterday took key administrative and military positions.

Since fighting peaked several hours ago it appears to have quietened, but residents of Myawaddy have reportedly been given an hour’s warning to evacuate the town before clashes resume.

The fighting has however spread south of Myawaddy to Payathonzu, across the border from Thailand’s Three Pagodas Pass. Major Mo Shae from the DKBA said that his troops there had captured nine soldiers from the junta’s Border Guard Force.

Nai Hongsa, general secretary of the New Mon State Party (NMSP), said that people were seen fleeing Payathonzu.

Additional reporting by Naw Noreen