The New York-based group Human Rights Watch is urging the UN Security Council to respond to attacks by the Burmese military on ethnic Karen civilians.
The group released a statement Tuesday saying thousands of Burmese are in need of help. It said without swift action by the Security Council, the killings and abuses in Burma will not stop.
Thai officials say at least 18,00 Karens recently crossed into Thailand to escape an offensive by Burma's military government. They are staying at a temporary camp near the border.
Last week, the U.S. State Department condemned Burma's actions against ethnic minorities, following reports that the military has displaced 11,000 members of minority groups.
The Karen, one of Burma's major ethnic groups, have been fighting for independence for more than 50 years. They have reached a provisional truce with the government, but sporadic fighting continues.