Zimbabwean police say they arrested six men accused of killing 41 elephants with cyanide, state media have reported.

Police official Muyambirwa Muzzah was quoted on Friday as saying rangers found several elephant carcasses after following tracks in the southwestern Hwange National Park.

Muzzah said a cache of tusks, worth $120,000 on the illegal ivory market, and other remains were found near water holes that had been laced with cyanide.

He said the six were arrested when they returned to collect the ivory and they are suspected of operating from the western city of Bulawayo.

The police official said hundreds of wild animals feeding on the dead elephants could also die from poisoning.

The Bulawayo Chronicle newspaper reported on Friday that poachers arrested in May for poisoning wildlife were jailed for two years.

The South African Mail and Guardian newspaper said poaching of elephants on the continent has increased substantially with a recent report saying at least 25,000 were killed last year.

The report also said the illegal ivory trade had doubled since 2007.

Source: Al Jazeera and agencies