Thousands of wild camels in Australia's Outback will be shot from helicopters as part of an attempt to control the animals' burgeoning numbers, a state official and local media said Tuesday.

Camels were first introduced into Australia (search) in the mid-1880s to transport supplies across the desert, but were released into the wild after trains and trucks replaced them.

With no natural predators and ample grazing land, Australia's wild camel population has exploded in parts of central, northern and western Australia. Some scientists have estimated there are as many as 500,000 camels roaming the country's vast deserts.

Authorities in South Australia state have announced plans to cull the animals, which have begun to encroach on rural properties.

Rural lands inspector Chris Turner (search) said camel numbers near ranching lands have reached about 60,000, straining the limited water supplies for sheep and cattle.

Turner said some ranchers have reported seeing as many as 200 camels drinking from a single watering hole.

"It's estimated that the camel population increases by about 11 percent per year," he told the Australian Broadcasting Corp. radio, adding that it was necessary to cap the animals' population.

"The simplest, quickest and most cost effective way of doing that is an aerial cull," he said.

Marksmen would be employed to shoot the animals from helicopters, the ABC reported on Tuesday.

The report said thousands of animals would be culled, but did not specify exactly how many.

Turner also declined to comment on the exact number.

Australia has a history of infestations by animals from overseas.

Rabbits brought from Europe swarmed across parts of the Outback (search) and noxious cane toads brought from South America to control bugs in sugar cane fields are now spreading across the north, killing native wildlife from snakes to small crocodiles that eat them.