In the last few days, hundreds of Karen tribesmen have fled into Thailand from Burma. The cause was a confrontation between several hundred Burmese troops and Karen rebels (of the Karen National Union). The ceasefire that was negotiated in late 2003 (but never signed) appears to have been broken. It is thought that a recent reshuffling of generals in the junta ruling Burma, brought about an effort to crush the last major tribal rebel group in northern Burma. These tribes have been hostile to the ethnic Burmese of southern Burma for centuries. When Burma became independent in 1949, the Karens were unhappy with their position in the new scheme of things, and organized a rebel force. This was easy to do at the time, because Britain and the United States had equipped and trained thousands of Karens to fight the Japanese during World War II. These battle hardened veterans now went after the Burmese down south, who had not fought the Japanese. The Karens, and other tribes in northern Burma, were able to keep the more numerous Burmese at bay for decades. But all that fighting wore them down, and in the late 1990s, the Burmese cut deals with most of the rebel tribes, leaving the Karen National Union as the only major rebel group operating. The fighting appears to have left several dozen men dead or wounded. The Karen are not happy because the Burmese troops in the area abuse the Karens, forcing them to work on government projects, and abusing the women.