MANAGUA, Nicaragua (AP) - The releases of gases from the San Cristobal volcano has prompted the government to order the evacuation of 500 nearby residents, Nicaraguan news media reported Wednesday. The 5,775-foot volcano, about 95 miles west of Managua, had been dormant for five years, before rumbling back to life Sunday with an eruption that left a thin layer of gritty, gray volcanic ash on four villages. Volcanic activity has diminished since the initial eruption, but government officials ordered the evacuations because of high toxic gas levels, local media reported.