Two men were killed and one woman injured after an altercation at a crowded Arizona restaurant on Friday (14 April) night led to shots being fired. Authorities said that the three individuals knew one another.

Pima County Sheriff's Department (PCSD) spokesman Cody Gress told reporters that the shooting was contained to the Firebirds Wood Fired Grill restaurant in the La Encantada mall in Tucson. Gress said one woman was shot in the leg and is being treated for non-life-threatening injuries at a local hospital.

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"All three individuals were known to each other, but the specifics of the relationship are unknown," he said. It remains unclear how the incident escalated into a shooting, authorities said.

In a statement, PCSD said that deputies determined the shooting was isolated to the restaurant and that no bystanders were injured.

"At this point in the investigation, it appears that one handgun was used," the statement said. "This was not a random incident and involved no other parts of the mall or surrounding establishments."

Witnesses told KOLD News 13 that they heard 10 shots before seeing a man turn a weapon on himself. Toni Escuibel, who was in the restaurant to celebrate her daughter's birthday, described the scene as chaotic.

"My husband turned around and said 'everybody under the table,'" Escuibel said. "[We] heard some screaming, some scuffling up at the bar. There were probably about 10 shots – and it was pretty harrowing. Pretty harrowing, not fun for young girls to have to go through that kind of experience."

Laura Harder, who was also in the restaurant during the shooting, told CNN affiliate KGUN-TV that she saw the two men fighting. "It looked like two gentlemen were fighting, it was hard to tell. I saw a gun come out and he just shot him in the head right in front of us," Harder said.

After one of the men was shot, the gunman allegedly grabbed the man's companion and pushed her down a hallway. Harder said she heard two more gunshots as she crawled away looking for an exit.

"I assumed he had shot her," she said.

Another witness, Barbara Sparrow, was eating at the nearby restaurant Raw Sushi when she saw people stream out of Firebirds while crying and screaming. Sparrow told KOLD News 13 that Raw Sushi went under lockdown and people were sheltered in the kitchen and office area.

Firebirds employees began ushering patrons out the back door to safety following the shots, witnesses said.

"They ushered everybody to safety and very orderly. I have to tell you that wait staff, the people inside Firebirds, did a great job handling everything," Escuibel said. "But now the aftermath, I have four very scared young women in the back of my car."