Missouri Walmart incident: Armed man who walked into store 'sparked panic'

US police have arrested a man who walked into a Walmart store in Missouri armed with a loaded rifle and 100 rounds of ammunition on Thursday.
Although the man, who also wore body armour, did not fire any shots, his actions sparked panic amongst shoppers.
The incident comes less than a week after a mass shooting in an El Paso Walmart in Texas, in which 22 people were killed by a gunman.
The man in Springfield was arrested after walking out of the store.
"An armed white male in his 20s was detained by an armed off-duty fireman until officers arrived on scene and took the suspect into custody," Springfield police said in a statement.
It was not clear what the man's motives were or whether he had committed a crime.
"His intent obviously was to cause chaos here, and he did that," Lt Mike Lucas of the Springfield police department told the Springfield News-Leader.
The 20-year-old man, who wore a bullet-proof vest and military-style clothes, was filming himself walking through the store and making comments to people while pushing a shopping trolley as shoppers fled around him, Lt Lucas said.
He was also carrying another gun, reports say.

On Wednesday, President Donald Trump visited El Paso, where a gunman had opened fire with an assault-style rifle in a crowded Walmart on the city's east side.
Nearby businesses were placed on lockdown and shoppers were evacuated.
In total, 31 people died in the attacks in El Paso and in the Ohio city of Dayton, which took place within hours of each other.