A violent brawl inside an In-N-Out Burger restaurant in Arizona sent terrified customers running as a group of teenagers exchanged punches in the dining room.The fight erupted at about 7 p.m. local time Monday at the beloved fast-food chain's Tempe location.The Tempe Police Department told Fox News Digital that officers responded to the scene, but the people involved had already fled on foot and in vehicles.CITIES BRACE FOR HOLIDAY WEEKEND TEEN TAKEOVERS PUTTING BYSTANDERS AT DEADLY RISK, FORMER PROSECUTOR WARNSVideo captured inside the restaurant shows a group of teens throwing punches and tackling each other to the floor as customers scrambled to get out of the way.The person who recorded the video noted that customers were "camping out" inside the restaurant at the time due to an active monsoon storm, affiliate FOX 10 Phoenix reported.INSIDE THE TEEN TAKEOVERS THREATENING TO EXPLODE THIS SUMMER AS CITIES REMAIN ON EDGE: 'VERY WORRIED'Investigators spoke with witnesses and staff, and a follow-up investigation is now underway.The cause of the brawl has not been disclosed, and Fox News Digital has reached out to the California-based chain for comment.The altercation closely mirrors a May brawl that happened inside a Chipotle restaurant in Washington, D.C.In that incident, teens dressed head-to-toe in black — some wearing hoods and masks — were seen throwing punches and hurling chairs as innocent bystanders sought safety.