A police tactics team surrounded a Greyhound bus along a major interstate northeast of Atlanta on Tuesday, prompting the highway to close in both directions for more than four hours before officers apprehended a man inside.

The SWAT team tried to negotiate with a man aboard the bus who was armed with a gun, Gwinnett County police said Tuesday.

Officers said the bus driver and all of the passengers aboard the Atlanta-to-New York bus were able to exit, but the man remained on board for hours, police spokesperson Ryan Winderweedle told reporters at the scene. Interstate 85 remained shut down in both directions Tuesday afternoon, The Atlanta Journal-Constitution reported.

Police received the call about a suspicious person with a handgun acting erratically around 9:30 a.m. Tuesday, Winderweedle said.

"We do not know what the suspect is wanting or asking for," he said. "The call came in that he was suspicious and acting erratic and then produced a handgun."

By Tuesday afternoon, the man was arrested, Gwinnett County police spokesperson J.R. Richter said. "There have been no injuries reported," Richter said in an email.

No other details were immediately released.

As the standoff unfolded earlier, Greyhound Lines Inc. said it was "working closely with local authorities to ensure the safety of our passengers and driver." The Dallas-based company said it had no further comment.

Tags: Georgia  Atlanta  I-85  Greyhound