Rangers killed a poacher in a Zimbabwe game park last week as security was stepped up at wildlife parks following this year's mass poisoning of elephants, wildlife authorities said Monday.

The Zimbabwe Parks and Wildlife Authority said the unidentified poacher was shot by rangers at Matusadonha game reserve, in the northwest of the country, during a shootout between the rangers and four poachers.

"One poacher, who is believed to be the gunner and had no identification particulars on him, was shot and seriously injured," said Caroline Washaya-Moyo, the parks spokeswoman.

The poacher was pronounced dead on arrival at a hospital in the resort border town of Kariba.

His three accomplices fled.

Zimbabwe has beefed up game park patrols after reporting the death of more than 100 elephants from cyanide poisoning in recent months. An independent wildlife conservation group puts the toll at 325.

Twelve people have been arrested in connection with the killings and five have already been handed prison sentences of a minimum of 15 years each.