Police in Tanzania say they are holding a total of nine suspects over the killing of a British helicopter pilot who was on an anti-poaching mission.

Simiyu regional police commander Lazaro Mambosasa said Monday that seven more suspects were arrested for the shooting death of Roger Gower, who was on a joint operation with Tanzanian wildlife authorities when he was shot. Gower died Jan. 29 in Maswa wildlife reserve, near Serengeti National Park.

Mambosasa said some of the suspects identified the man who pulled the trigger. Three elephant tusks and 29 firearms were seized in the operation to arrest Gower's killers.

Tanzania has been identified as a key hotspot for elephant poachers.