A conservation group operating in Tanzania says a total of five people have been arrested for the shooting death of a British pilot who was flying a helicopter on an anti-poaching mission.

The Friedkin Conservation Fund said Friday that more arrests are expected following the killing of Roger Gower, who was flying on a joint operation with Tanzanian wildlife authorities when he was shot. Two days after Gower's death, it announced three arrests in an ongoing security operation.

The Texas-based Friedkin group says detainees include a suspected gunman and accomplices, as well as members of a network providing illegal weapons and smuggling ivory.

Gower died Jan. 29 in Maswa wildlife reserve, near Serengeti National Park. The Friedkin group oversees conservation projects in Maswa and some other wildlife areas in Tanzania.