Streets surrounding the U.S. Capitol and congressional office buildings were locked down, with a heavy police presence, on Friday, a Reuters eyewitness said, while Capitol police said they were responding to reports that a motorist had tried to run down two officers.

Capitol police said they were responding to reports that someone rammed a vehicle into two officers and a suspect was in custody. “Both officers are injured. All three have been transported to the hospital,” their statement said.

Dozens of police cars, marked and unmarked, raced toward the Capitol building. All roads leading to the complex were blocked by police or police officers.

A helicopter was seen hovering overhead and observers were ordered to leave the area. Videos from the scene showed what looked like two people on stretchers being loaded into ambulances.

Authorities have begun only in the past couple of weeks to remove the outer ring of high, razor-wire-topped fencing erected around the sprawling Capitol complex after an attack on Jan. 6 by thousands of supporters of then-President Donald Trump.

Reporting by Idrees Ali and Patricia Zengerle; Editing by Chizu Nomiyama and Howard Goller / REUTERS