Authorities in Congo have arrested six people in connection with the dumping of radioactive waste in a river in the country's southeast.

Residents of the Congolese town of Likasi have been told to avoid using the Mura River to drink or bathe, and to prevent their livestock from drinking the water.

Officials in the southeastern province of Katanga discovered the dumping earlier this week. They say the river has a radioactivity level 50 times over the safe legal limit.

Media reports say local authorities had seized 17 tons of radioactive material last month and ordered its safe disposal. The reports say that at least some of the waste was dumped into the river instead.

Democratic Republic of Congo Environment Minister Didace Pembe says the waste belongs to a Chinese company, Magma-Lubumbashi, but adds the company did not request the material be dumped in the Mura.

Rocks and soil mined near Likasi typically contain small amounts of uranium.