(DALLAS) —  A gunman who appeared to be wearing tactical gear and wielding an assault rifle opened fire outside a federal courthouse in Dallas Monday morning, but no one aside from the alleged shooter appeared to be injured in the incident, police said.Police responded to what they called an active shooter incident at the Earle Cabell Federal Courthouse in downtown Dallas at 8:50 a.m.”There has been an exchange of gunfire between a suspect and federal officers,” the Dallas Police Department wrote in a post on Twitter. “The suspect was shot and transported to an area hospital. No officers or citizens injured.”The alleged gunman, identified by federal authorities as 22-year-old Brian Isaack Clyde, was gravely wounded in the gunbattle with Federal Protective Service officers, said Matthew DeSarno, special agent in charge at Federal Bureau of Investigation Dallas/Fort Worth office. Clyde was taken to Baylor University Medical Center, where he was pronounced dead, DeSarno said at a news conference.Cell phone video taken by a witness and shared with ABC News appeared to show the gunman dressed black tactical gear, including a bulletproof vest. The video shows him taking up a position on one side of the courthouse, peeking around a corner and pointing a rifle.The gunman is then seen running through a nearby parking lot, where the gunbattle apparently occurred.Police have yet to comment on a possible motive for the shooting.”At this time, we have no information indicating that there are other shooters, other threats to the community,” DeSarno said.The federal courthouse and nearby El Centro College were immediately placed on lockdown, according to ABC affiliate WFAA.Police bomb squad technicians were examining the suspect’s car found parked on a street near the courthouse. Dallas police said on Twitter that they were preparing to do a controlled explosion of that vehicle, but offered no further details.Aerial video showed a bomb squad robot examining the gray vehicle.Witness Don Miles told WFAA that he was walking into the courthouse for a hearing when the shooting broke out and people inside the building began streaming out.”I was walking up to the building and all of a sudden there was shooting, rapid shooting,” Miles said. “I didn’t see anybody get shot, but I did hear all the shooting. It was like 10 to 15 shots all of a sudden, at one time.””I was walking up to the building and all of a sudden there was shooting, rapid shooting,” Miles said. “I didn’t see anybody get shot, but I did hear all the shooting. It was like 10 to 15 shots all of a sudden, at one time.”The shooting was monitored by police as far away as New York.”We continue to closely monitor the reports of an active shooter at the Earle Cabell Federal Building in Downtown Dallas, Texas,” the New York Police Department counterterrorism unit tweeted. Copyright © 2019, ABC Radio. All rights reserved.