(GABORONE, Botswana) — Botswana says it is investigating a staggeringly high number of elephant carcasses — 275 — found in the popular Okavango Delta area of the southern African nation in recent weeks. The Department of Wildlife and National Parks said it is mobilizing human personnel and aircraft to better understand the “mysterious deaths.” Samples have been collected for analysis at labs in South Africa, Zimbabwe and Canada and anthrax has been ruled out as the cause. “We have no reason to dispute the numbers reported and we are continuing to verify reports,” Lucas Taolo, the department’s acting director, told The Associated Press. He said local communities are being advised not to tamper with the dead elephant’s tusks.