U.S.-backed contras shot down a Soviet-supplied helicopter gunship, killing all three crew members, Nicaragua's Defense Ministry said. The MI-25 helicopter was hit as it supported Sandinista troops fighting in central Nicaragua, the ministry said. It was the first time that Nicaragua has publicly acknowledged the loss of an MI-25, one of the Soviet Union's most advanced helicopters. According to the government, the copter was the third one shot down since 1985. The contras say they have downed more than six.