The Kenya Wildlife Service on Friday said its agents shot dead two suspected poachers who they saw shooting at a herd of elephants in one of the country's famous national parks.

This brings the number of poachers shot dead by agents of the wildlife service to five, the most killed in a month, said spokesman Paul Udoto.

He said rangers gunned down the two suspected poachers and recovered one firearm on Thursday at the Amboseli National Park, a key sanctuary for animals in southwestern Kenya.

Udoto said three others escaped with injuries. The gang is suspected of involvement in the killing of two elephants in the same area three weeks ago. Poachers target elephants for their ivory tusks, which are often smuggled to Asia.

"We want to make poaching a high-risk and low-benefit business," Udoto said. "Anybody who engages in poaching or trafficking of (wildlife) trophies will have a very difficult life and including losing their lives."

Udoto said rangers shot the poachers as a self-defense measure.

"We are encountering incidents that put our rangers in great risk," he said. "And in such incidents, self-preservation takes precedence."

He said the wildlife service would rather capture suspected poachers and charge them in court, where they can gather information that can lead to other participants in the ivory trade.

Two weeks ago KWS rangers killed a suspected poacher who was found cutting off tusks from a dead elephant at Meru National Park in central Kenya. Days earlier rangers shot and killed two suspected bandits in Tsavo National Park in eastern Kenya after they engaged rangers in a shoot-out after they were found with pieces of ivory from four elephants.

Wildlife officials said elephant poaching has risen sevenfold in Kenya since a one-time ivory sale was approved in 2007 by CITES, the Convention on International Trade in Endangered Species, for four African countries. Last year 271 Kenyan elephants were killed by poachers, compared with 37 in 2007 according to the KWS.

The elephant populations of many African countries were being decimated until a global ban on the ivory trade was implemented in 1989. Since then the elephant population of Kenya has grown to 35,000 this year, from 16,000 in 1989.

The increased number is still lower than the estimated 167,000 elephants that roamed Kenya in 1973.