A mass shooting has taken place in the US state of Kansas, police say.

The suspected gunman was an employee at a lawnmower factory in the town of Hesston, police said. He was later killed by officers.

Up to 20 people were injured in the attack at the Excel Industries factory, County Sheriff T Walton said.

Sheriff Walton said up to four people may have been killed but local reporters tweeted that the only person confirmed dead was the gunman.

Local TV station KSN-TV showed police vehicles at the factory and at least one person being loaded into an ambulance.

'He looked right at me'

Factory employee Martin Espinoza described how the gunman, a colleague who he said usually had a calm demeanour, attempted to shoot him.

The gunman pointed his gun at Espinoza and pulled the trigger, but the weapon was empty. Mr Espinoza then ran away as the gunman took out a second gun.

"I looked right at him and he looked right at me," Espinoza said.

Another witness described scenes of panic.

"All I know is I'm seeing people running and so I'm assuming fire, and so I take a few steps and I hear pop, pop and I'm thinking just some paint cans or something going up, and more people running and all of a sudden, pop, pop, pop, pop, pop, pop, pop, pop, pop and I'm going, ahh, I start running too," said one man.

The sheriff said there were "a number of crime scenes involved" in the incident.

"There's going to be a lot of sad people before this is over," he said.

(BBC)