Berrien County Sheriff's Deputies and Michigan State Police stand guard at Berrien County Courthouse where several people where shot this afternoon on July 11, 2016 in Saint Joseph, Michigan. [Photo/VCG]

CHICAGO -- A US inmate shot dead two bailiffs on Monday at a courthouse in the state of Michigan before responding officers returned fire and killed him, authorities said.

A deputy sheriff and a civilian were also shot and wounded in the shooting at the Berrien County Courthouse in St. Joseph city, about 160 km from Chicago, Berrien County Sheriff Paul Bailey said at a news conference.

The shooting occurred at 2:25 p.m. on the third floor of the courthouse when the inmate being moved to the courthouse grabbed a gun from a law enforcement officer and opened fire.

The identity of the inmate was not released. But Bailey said that the inmate had been in custody for "several charges."

The deputy sheriff was rushed to hospital for treatment and was in stable condition, he said.

An investigation was underway, Bailey said.

The shooting came amid tensions across the United States following the killing of five police officers in Dallas, the state of Texas, last week by an Army veteran upset about the fatal police shootings of two black men in the US states of Louisiana and Minnesota.

The police shootings in Louisiana and Minnesota have ignited nationwide protests by African Americans against police brutality and racial discrimination.