During conflicts, Shan civilians are often burned out of their villages and forced to flee into Thailand. Some of the worst fighting in recent times occurred in 2002 when the Burmese army shelled the Thai border town of Mae Sai, south of Tachileik, in an attempt to capture members of the SSA's Southern Faction who had fled across the Nam Ruak. While in July of that same year, in the Shan Township of Mong Yawng, the killing of a member of an NGO by the Burmese Tatmadaw, and the subsequent closure of the border to Thailand, caused an evacuation of the surviving members across the Mekong River to Laos. This evacuation was aided by members of the Shan State Army, and in turn brought tighter measures restricting foreign aid in the area as violence increased.