HARARE, Zimbabwe – Poachers are using aircraft to hunt and kill rhinoceros, Zimbabwe's wildlife chief said Tuesday, as demand in Asia for their horns' supposed medicinal benefits grows.

Seven endangered rhinos were killed in southern Zimbabwe from early December to Jan. 19, representing about one-third of all 22 rhinos poached throughout 2010, Parks and Wildlife director general Vitalis Chidenga.

He said the poachers, including local recruits, were well-equipped with sophisticated weapons. Five of the rhino were shot in one park in the southwestern Matabeleland province, he said.

Rhino horn is prized in Asia as a traditional cure for everything from colds to impotence and it is used to fashion ceremonial dagger handles in oil-rich countries in the Middle East.

Chidenga said the southern African nation has about 1,000 surviving rhinoceros, and that extra rangers and soldiers are being sent into their habitats to protect them.

Evidence from sites of the recent killings in Zimbabwe showed poachers were "well-organized and well-funded." Some "big money" syndicates even used light aircraft for poaching missions and reconnaissance.

"This is a regional onslaught and not isolated incidents," Chidenga told The Associated Press.

Wildlife officials in neighboring South Africa say 2010 was an extraordinarily bad year, with 333 rhinos poached, nearly three times as many as were lost in 2009. Five more rhinos were killed in the first weeks of 2011.