At least three people have been taken to hospital after a gunman opened fire at a Greyhound bus station in Richmond, Virginia.
Two Virginia state troopers and a female civilian were shot in the attack, said police spokeswoman Corinne Geller.
She said a male suspect was in custody after the attack on Thursday afternoon.
Ms Geller gave no details on the condition of the casualties.
A local NBC station is reporting that six people have been injured, two critically.
NBC12’s Mike Valerio quotes police sources as saying a man walked up to an officer and shot him in the chest.
US Homeland Security officials are at the scene among dozens of officers, reports a local CBS station.
According to the Richmond Times-Dispatch, witnesses reported seeing up to 10 muzzle flashes from gunfire.
The station is on a main road near the city centre, a minor league baseball stadium, a residential district and restaurants.