Police in the US say a gunman who murdered five people and wounded several others at a warehouse in Illinois launched his killing spree as he was being fired from the company.

The killer has been named as 45-year-old Gary Martin.

He had worked at the Henry Pratt manufacturing company in Aurora, Illinois for 15 years.

He was shot dead following the killing spree after police responded to reports of an “active shooter” at around 8pm Irish time last night.

Aurora Police Chief Kristen Ziman said Martin was armed with a handgun.

It is not yet clear whether he was carrying the weapon while he was being fired or if he went to retrieve it before opening fire.

Illinois

The five victims were all employees at the Henry Pratt Company, which makes valves for industrial purposes.

A sixth worker was taken to a hospital with non-life threatening injuries.

Five police officers were wounded after being shot as they entered the building, while a sixth officer suffered a knee injury but was not hit by gunfire.

The officers who were shot are described as being in a stable condition in hospital.

Authorities search an apartment complex where the gunman who fatally shot several people at a manufacturing complex is believed to have lived, 15-02-2019. Image: Patrick Kunzer/Daily Herald

Gunman

Police Chief Ziman said she did not have information about whether the gunman had a criminal history, but public records showed Martin was convicted in 1995 for aggravated assault in Mississippi.

A woman who identified herself to police as Martin's mother told authorities her son was "stressed out" about losing his job, the Chicago Sun-Times newspaper reported.

Witness John Probst said he recognised the gunman, who had "a pistol with a laser," as someone who works at the company.

Mass shooting

The attack happened a day after the first anniversary of a school shooting in Parkland, Florida, which left 17 people dead.

Aurora Mayor Richard C. Irvin said: "It's a shame that mass shootings such as this have become commonplace in our country.

"It's a shame that a cold and heartless offender would be so selfish as to think he has the right to take an innocent life."

US President Donald Trump praised the response of emergency crews to the mass shooting.

He tweeted: "Great job by law enforcement in Aurora, Illinois. Heartfelt condolences to all of the victims and their families. America is with you!"