By Gina Cherelus
(Reuters) - Several people were shot on Thursday in Perryman, Maryland, near an Army facility, and residents were asked to avoid the area, according to authorities.
"The situation is still fluid," the Harford County Sheriff's Office wrote on Twitter, adding that officers were dispatched to the incident shortly after 9 a.m. EDT (1300 GMT).
Agents from the Baltimore offices of the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) and the FBI were also responding, the agencies said.
Perryman is 34 miles (55 km) northeast of Baltimore. The area of the reported shooting includes a church and a business district, and is near the Aberdeen Proving Ground, an Army facility.
Details of the shooting were still largely unknown around 10:30 a.m. (1430 GMT).
A witness told NBC's affiliate in Baltimore that the shooting occurred in a warehouse and that 20 to 30 officers, as well as ambulances, responded to the scene.
"They're telling that there is an active shooter," said the witness, whom the station identified as a man named Bo who did not want to provide his last name.
Governor Larry Hogan said his office was "closely monitoring the horrific shooting."
"Our prayers are with all those impacted, including our first responders," Hogan wrote on Twitter. "The State stands ready to offer any support."
The shooting occurred a day after a man shot and wounded four people, including a police officer, at a Pennsylvania court building before he was killed by police, according to Pennsylvania State Police.
(Reporting by Gina Cherelus in New York; editing by Jonathan Oatis)