An "erratic" driver sparked a security alert near US Congress after ploughing into a police car and almost mowing down several officers.

Police fired shots at the "dangerous" driver as she rode towards them not far from Capitol Hill on Wednesday, according to NBC.

The female who was behind the wheel attempted a u-turn after smashing into a police car, only to then narrowly avoid hitting a number of officers moments later.

After the incident the woman, in her twenties, was taken into custody.

Police said the incident was not thought to be related to terrorism.

The scare prompted the closure of several roads surrounding Capitol Hill.