Leaders of a Southern California Indian tribe plan to sit down with sheriff’s deputies to calm tensions over the killings of four people on the reservation.

Federal mediators are to take part in Friday’s session with Riverside County sheriff’s deputies and members of the Soboba tribe.

The meeting comes four days after two people opened fire on security guards outside the tribe’s casino and led deputies on a chase into the hills of the reservation. Authorities say the man and woman fired at a sheriff’s helicopter and SWAT team before officers killed them.

Deputies also have killed two sons of a former tribal chairwoman recently.

Officers claim they are frequently under fire on the reservation southeast of Los Angeles.