Based on intelligence inputs, troops of army's Red Horns Division and police jointly conducted an operation when the encounter took place near village Kongkhal, a Defence officer said.
Two 7.65 mm pistols, two hand grenades, a large amount of ammunition and other war-like stores were recovered during the operation, the officer said.
The United Achik Liberation Army is a breakaway faction of Achik National Volunteer Council which on December 15 laid down arms in front of Meghalaya government, the sources said.