Nine people have been wounded in a shooting on a crowded beach in Florida over the US Memorial Day holiday. The shooting on Monday evening unfolded on the Hollywood Oceanfront Boardwalk, a popular area for beachgoers 20 miles (32km) north of Miami. Police said shots broke out during an altercation between two groups. Those injured range in age from one to 65, and the wounded includes four children, police said. One person was arrested, police spokesperson Deanna Bettineschi said. Authorities continue to search for a second suspect. Police said on Tuesday that they had obtained surveillance footage from the site showing the two people believed to be responsible for the shooting. Video and images were released to the public in an appeal to identify the suspects. Bettineschi said police first received reports of gunshots around 18:42 local time (23:42 BST). "We know there was a dispute between two groups, and that's when the gunfire had started," she said. The four children wounded are between the ages of one and 17, and the five adult victims are between the ages of 25 and 65. Memorial Regional Hospital and Joe DiMaggio Children's Hospital told US media that six patients — four minors and two adults — remain in hospital in stable condition. Three adults were treated and discharged, they said. Hollywood police chief Chris O'Brien told reporters that thousands of people were in the area at the time of the incident and dozens of police officers responded to the shooting. In a statement, Hollywood Mayor Josh Levy said he was "deeply saddened" by the shooting. "It is completely unacceptable that innocent people spending time with family on a holiday weekend have been affected by a shooting altercation between two groups who came into our city with guns and with no regard for the safety of the law-abiding public around them," Levy said. It is the 263rd mass shooting in the US this year — defined as shootings in which four or more people are injured or killed — according to the Gun Violence Archive. Chicago was also marked by gun violence over the Memorial Day weekend. At least nine people were killed and over 40 people wounded in the city between late on Friday and early on Tuesday. Two young children are among those injured. One two-year-old accidently shot herself in the hand on Sunday evening after finding a handgun in a local park, Chicago police said. In another case, a two-year-old boy was playing in his bedroom when a gun went off. He was also shot in his hand. Both children are recovering, officials said. — BBC