Thousands have fled across Myanmar's border to escape clashes between troops and ethnic Karen rebels, following the country's first election in 20 years.
Thai officials say more than 10,000 people have fled the fierce fighting in and around the town of Myawaddy which erupted in a protest linked to Sunday's election.
Several people have been killed and injured in battles between the rebels and government troops. Thai army bases are providing temporary shelter to the thousands of refugees.
The poll, boycotted main opposition group the National League for Democracy, was marred by campaign restrictions, reports of irregularities and low turnout.
Many ethnic groups were excluded from the election and there were warnings that a flare-up in long-running border insurgencies may occur after the poll.
There has also been fighting further south on the Thai-Burma border near Three Pagodas Pass.
Votes are still being counted, but early results point to a victory for the party closely linked to Myanmar's current military government.