One person has died and three others have been injured following a shooting incident at a synagogue in Poway north of San Diego, the city's mayor has said.

"We had four folks with gunshot wounds. We do have one fatality. The rabbi was shot in the hand. My understanding is none of the other injuries are life threatening," Mayor Steve Vaus told cable news network MSNBC.

A man has been detained for questioning in relation to the shooting.

San Diego Sheriff Bill Gore the synagogue was hosting its Passover Holiday Celebration, which was scheduled to begin at 11am local time.

The shooting comes exactly six months after a gunman killed 11 people at a synagogue in Pittsburgh, the deadliest attack on the Jewish community in the history of the United States.