Gas station workers were arrested on assault charges after videos showed them engaging in a violent encounter with customers, Pittsburgh police said.

Cellphone footage and surveillance video showed three men beating two women last week in a confrontation that began over spilled gas at an Exxon station on Sept. 20, according to authorities. Pittsburgh police said that the argument began when customers demanded a refund when a pump malfunctioned and were refused.

One of the two women, who were not identified by police, was seen in the station's surveillance footage knocking over a display inside the store. It appeared that the fighting began in the store, then moved outside to the pumping stations.

Video captured by a bystander outside showed the men yelling about getting the women's license plate number as they exit the station. Then things quickly escalated as one of men who worked in the gas station hit one of the women in the back of the head multiple times.

Both women were slammed to the ground and hit repeatedly by the men. One of the women was held to the ground by one man while another hit her.

Witnesses in the background yelled out, "That is a girl, don't mess with a girl."

All three men, identified by police as the gas station owners and an employee, were arrested and charged with simple assault.

After footage of the fight went viral, protesters attempted to close the gas station and called for harsher charges against the men.

Allegheny County District Attorney Stephen Zappala defended the simple assault charges and said Wednesday that the altercation did not escalate to aggravated assault, according to NBC affiliate WPXI.

The defense attorney for two of the men, David Shrager, said Thursday that his clients were gas station employees that have had no prior criminal record, according WPXI. They have since been suspended without pay.

The Pittsburgh Police Department did not immediately respond to a request from NBC News for more information.