FERGUSON, MISSOURI — A man was gravely wounded in a gun battle with police in Ferguson, Missouri on Sunday night after a day of peaceful rallies to mark the fatal shooting of an unarmed black teenager by a white officer one year ago. Several volleys of gunshots rang out as police in riot gear tried to disperse demonstrators blocking traffic and smashing storefront windows along a street that was a flashpoint of last year's unrest in the St. Louis suburb after Michael Brown, 18, was slain. Police later said the gunfire began with two groups of agitators apparently shooting at each other. When one gunman ran across a parking lot, four police detectives pulled up in an unmarked vehicle and confronted him. The suspect opened fire on the police vehicle and was badly wounded in the ensuing foot chase and exchange of gunshots with the four officers, police said. St. Louis County Police Chief Jon Belmar said the unidentified man, believed to be in his mid-20s, was hospitalized in critical and unstable condition, and was undergoing surgery. Speaking to reporters at a predawn news conference on Monday, Belmar estimated that more than 40 rounds had been unleashed in what he called “a remarkable amount of gunfire.” “These were criminals, they weren't protesters,” he said of the shooters. “There is a small group of people out there that are intent on making sure that we don't have peace that prevails.” Police initially had reported two people shot Sunday night. But Belmar later said a police officer was struck in the face with a brick hurled by protesters and a member of the local news media was also robbed and assaulted in a nearby parking lot in separate incidents amid Sunday night's turmoil. — Reuters