On Saturday, the Karen National Union condemned the use of "excessive force by engaging in non-stop bombing and air strikes" from March 27 - 30, which have "caused the deaths of many people including children".
The US, Britain and the EU have all imposed sanctions in response to the crackdown, but so far diplomatic pressure has not persuaded the generals to ease off. The UN Security Council is set to meet for emergency talks on Wednesday.
At about 4 am Friday, an attacker hurled a Molotov cocktail at the National League for Democracy headquarters in Yangon, causing a brief fire that was put "under control" within an hour, a party official said.
The Kayin State Border Guard Force has come under intense pressure from the Tatmadaw over its extensive, controversial business interests and there’s concern the ultimatum could trigger fresh hostilities in one of the country’s most war-torn areas.