Numerous shoppers were inside making their purchases when the armed assailant entered and fired several shots.
Supermarket employees said he fired at least six shots during the terrifying ordeal.
AGENTS CAME OUT WITH A VEST SHOUTING AND PUSHING THE PEOPLE
Police arrived at the scene to arrest the attacker.
One witness told local media: “Agents came out with a vest shouting and pushing the people.”
A horrified witness is consoled outside the store
The 38-year-old revealed the attacker was only apprehended after his colleagues arrived.
The incident took place in a Mercadona shop, in As Lagoas
Police sources told local media the gunman, who has been previously arrested, is believed to have psychological problems.
Local media reported that the attacker had been living in the area for six months and had previously shopped in the supermarket.