The 1990s turned the gorillas' habitat into a battle ground. Tutsi rebels used the thickly forested Virungas as cover to sneak between Rwanda and Uganda, and in 1991 they used the park as a base to launch attacks on Ruhengeri. In response, the government sent patrols into the region, laid land mines and at one point cleared a 300-foot wide section of bamboo forest to reduce the chances for ambush along a key trail. The two sides skirmished, and often park staff was caught in the middle.