Two people have died during protests over the police shooting of a black man in Wisconsin, USA.

Footage posted online showed people running through the streets of Kenosha, Wisconsin, as gunshots rang out, while videos showed wounded men lying on the ground.

It came during a third night of protests over the case of black man Jacob Blake, who was seen in a video being shot up to seven times at point-blank range by a white Kenosha police officer on Sunday.

Blake was trying to get into his car, with his three children inside, when he was shot.

Referring to the deaths during the protests, Sheriff David Beth said one victim was shot in the head and another in the chest.

At least one small group of mainly white, heavily armed men was in the city on Tuesday night vowing to protect property.

The New York Times reported police were investigating whether the Tuesday night shooting "stemmed from a conflict between self-styled militias guarding a gas station and demonstrators".