In addition to the disparity in population, there was also a great disparity between the fighting capabilities of the armed forces of the two countries. In 1977, Vietnam was estimated to have 615,000 soldiers and 900 tanks, supported by a 12,000-member air force with 300 combat aircraft, including one squadron of light bombers. In comparison, Kampuchea had an army of 70,000, only a few heavy tanks, 200 armoured vehicles and limited air capability. Despite facing such heavy odds, Kampuchea showed no signs of hesitation as its military continued to assault Vietnam's border regions. In January 1978, KRA forces still held portions of Vietnamese territory and began overrunning Vietnamese outposts in Hà Tiên Province. On 27 January 1978, Vietnam started calling on the KRA along the border regions to overthrow the Khmer Rouge government.