A man has been shot dead in Nigeria's north-eastern Bauchi state while a so-called bullet-proof charm - or "gun medicine" - was being tested on him by a traditional healer, police spokesman Ahmed Wakil has said.

The healer - who allegedly fired the shot with a locally made gun - has been arrested, along with two other suspects, while other suspects are on the run, he added.

The test on the efficacy of the "gun medicine" occurred on 43-year-old villager Muhammadu Ali, Supt Wakil said.

Police rushed to the scene as soon as they heard of the shooting, and took Mr Ali to hospital, but he was pronounced dead on arrival, the police spokesman added.

He warned the public against being used as "cannon fodder".

The suspects will be charged to court after investigations are concluded, Supt Wakil said.

Charms believed to have magic powers are commonly used in Nigeria, where many people consult traditional healers over a wide variety of issues.

But there have been several reports of people being killed after testing so-called bullet-proof charms and medicines.