About 10,000 refugees have fled from Burma into Thailand as a result of fighting between ethnic rebels and the Burmese military, a day after the country's landmark election.

A number of people have been killed and injured in the fighting between Karen rebels and Burmese government troops.

A market in the Burmese border town of Myawaddy was hit with mortar rounds, killing three.

A wayward grenade also struck on the Thai side of the border where the riverbank has now been evacuated.

Thai army bases are providing temporary shelter to the thousands of Burmese people who have fled the fighting.

Many ethnic groups were excluded from yesterday's 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.

International condemnation

Many Western powers have called yesterday's election a fraud.

They are continuing to allege that ballot boxes were unsealed and stuffed, and that public servants were watched by officials to make sure they voted for the military's party.

Vote counting is now underway, but the new civilian parliament is set to remain dominated by members of the military junta.

Foreign Affairs Minister Kevin Rudd is among many international politicians to have condemned the poll.

"These elections have been far from free and far from fair. A number of democratic parties have participated and we will be watching very closely what emerges from the Burmese political process," he said.

"The people of Burma deserve much better than the regime they have got."

Britain's ambassador, Andrew Heyn, says the whole process in Burma is flawed.

"There's a kind of joke doing the rounds here, that this is less of a general election than an election of generals," he said.

"And I think that kind of speaks volumes for the way a lot of Burmese feel about this.

"The constitution contains some major flaws, not least the 25 per cent military block as nominated military officers may be elected in the parliament."