The Tanzanian man flew into a rage after losing some USD 300 at a casino in Nairobi's Eastleigh district in the early hours of today morning, and attacked a manager after she refused to lend him cash to continue to play.
He then left the casino and returned with a sword.
"He first attacked a female manager who declined to lend him money to continue gambling, and that is when he went out to fetch a sword and slashed her to death," Nairobi police chief Japheth Koome said.
Another security officer was wounded, but other gamblers then chased the attacker before beating him to death in the street using rocks.
"By the time our officers arrived, they found him dead," Koome said.
Gambling is becoming increasingly popular in Nairobi.