Los Angeles, April 8 (Inditop) One person was killed and three wounded when a lone gunman opened fire at a Korean Christian retreat in Riverside County near Los Angeles, the police said.

The shooting took place Tuesday at the Kkottongnae Retreat Camp after sunset, Riverside County sheriff’s spokesman Dennis Gutierrez said.

Among the wounded, at least two were in critical condition. The gunman was believed to be among the injured, Gutierrez said.

The motive behind the shooting was not immediately known, Gutierrez said.