Four men were arrested on a beach in Kobe after they went on a rampage and sprayed tear gas at a convenience store, injuring nine bystanders, police said.

Joshua Hitsuwari, a 20-year-old man with Filipino nationality, and three other young men were arrested on suspicion of inflicting injuries on the nine victims Sunday evening at a convenience store near popular Suma Beach, the police said.

The victims were transported to area hospitals after being exposed to the gas, with some sustaining facial injuries, the police said.

The police were initially unaware of what touched of the brawl. At one point, Hitsuwari allegedly kicked the face of a 20-year-old office worker from Nishinomiya, Hyogo Prefecture.

According to witnesses, two groups started a fight, hitting each other with umbrellas that were being sold in the convenience store and throwing shopping baskets. Tear gas was sprayed as the fight escalated, they said.

Suma Beach is a popular summer spot in the Osaka-Kobe area due to its location close to both cities.