Multiple people were shot in an incident Thursday in the US city of Indianapolis, according to police, although the severity of the victims' injuries was not immediately clear.

Police spokeswoman Genae Cook told reporters  officers found an "active shooter incident" at a Fedex facility near the city's international airport, and believe the gunman died by suicide.

Police said multiple people had been shot but did not confirm the number or their status.

Sgt John Perrine, an Indiana State police public information officer told relatives of Fedex employees to gather at a local Holiday Inn.

Live video showed police tape at the scene of the incident, which follows several mass shootings in recent weeks.

At the end of last month, four people, including a child, were shot dead in an office building in southern California.

On March 22, 10 people were killed in a shooting at a grocery store in Boulder, Colorado. 

That came less than a week after a man shot and killed eight people, including six women of Asian descent, at spas in Atlanta, Georgia.

Nearly 40,000 people in the United States die each year from guns, more than half of those being suicides.

The issue of gun regulation in the United States is politically fraught.

President Joe Biden this month announced six executive measures he said would help stem the gun violence crisis.

The moves were immediately attacked by Republicans, with the party's senior leader in the House of Representatives, Kevin McCarthy, warning of "unconstitutional overreach."