Washington, Aug 25 (IANS): Unrest continued in the US state of Wisconsin after an African-American man was shot by the police in Kenosha city.

On Monday, protesting crowds tried to cram into the city's Public Safety Building for a news conference, knocking a door off its hinges, reports Xinhua news agency.

Riot police tried to disperse the crowds with tear gas and pepper spray.

Kenosha Mayor John Antaramian confirmed more than 100 Wisconsin National Guard members had been deployed in the city by late Monday due to the violence.

A video posted on social media shows 29-year-old Jacob Blake walked to a grey van followed by two police officers with weapons drawn.

As Blake opened the door to get in, an officer grabbed Blake's shirt to hold him still, and shot him at close range in the back at least seven times.

Blake was in stable condition Monday after surgery, his father said.

Protests erupted immediately after the shooting on Sunday evening.

At least three garbage trucks were burned out and windows were shattered at several businesses.

A police officer was injured by a brick, said the mayor at the news conference on Monday.

In a statement released on Monday, Democratic presidential candidate Joe Biden said the shots "pierce the soul of our nation".

"Equal justice has not been real for Black Americans and so many others. We are at an inflection point. We must dismantle systemic racism," he added.

The Division of Criminal Investigation under the Wisconsin Department of Justice is investigating the case.

"We understand that there is a need for this investigation to move swiftly," Wisconsin Attorney General Josh Kaul said at the news conference.

The division aims to provide a report on the incident to the prosecutor within 30 days.

The Blake family has retained civil rights attorney Benjamin Crump to represent them.

Crump also represented George Floyd's family after the latter, an unarmed African-American man, was killed by police brutality on May 25 in Minneapolis, Minnesota.