Officials say one person was rushed to the hospital with a serious stab wound following an early morning incident on the south side.

SAN ANTONIO — A man was injured early Thursday morning in a stabbing at a south side gas station, and police are continuing to investigate what led up to the incident.

According to the San Antonio Police Department, officers were called just before 5:40 a.m. to a Circle K in the 1500 block of Southwest Military Drive near Commercial Avenue.

Police say the incident began as a fight between a customer and an employee inside the store. During that altercation, the customer—believed to be a man in his 30s—was stabbed.

He was taken to the hospital with injuries that are not considered life-threatening.

Authorities say the employee involved is a man in his 40s. It’s still unclear what led to the confrontation or who initiated the violence.

The scene was heavily secured Thursday morning, with multiple police units and crime scene investigators processing the area. Officers have taped off the gas station and are working to review surveillance video from inside the store.

Police also say at least one eyewitness is cooperating with investigators.

The investigation remains ongoing.