Multiple shots fired at Capitol Hill, one policeman injured

The US Capitol, the seat of Congress, was locked down today after a female suspect fired multiple shots outside the building after she was chased there in her car from the White House, where she tried to ram a security barricade.

A police officer was injured after 10-12 shots were reportedly fired outside the Capitol Hill, Kim Dine of the Capitol Police told reporters. It is thought it was an "isolated incident" and not terrorism, he said.

The incident sparked a massive security response, emergency vehicles converged on the scene and security was heightened inside the Capitol, which was already tense during shutdown negotiations.

President Barack Obama was briefed on the reports of gunfire on Capitol Hill this afternoon, according to a White House official.

Media reports said a child was in the black car with the female suspect who tried to drive through the barricade that blocks the stretch of Pennsylvania Avenue in front of the White House to vehicles. The driver then proceeded down Pennsylvania Avenue to Capitol Hill, where shots were fired after a high-speed police chase.

The woman suspect was reportedly shot dead. "White House staff are in touch with law enforcement and monitoring the incident. Questions about the security posture at the White House complex should be directed to the United States Secret Service," according to a White House official.

In an email, the Capitol Police wrote that gunshots have been reported on Capitol Hill requiring all occupants in all House Office Buildings to shelter in place.

"Close, lock and stay away from external doors and windows. Take annunciators, Go Kits and escape hoods; and move to the innermost part of the office away from external doors or windows," the email said.

"If you are not in your office, take shelter in the nearest office, check in with your OEC and wait for USCP to clear the incident. No one will be permitted to enter or exit the building until directed by USCP.

"All staff should monitor the situation. Further information will be provided as it becomes available," the Capitol Police said.

Media reports earlier said the White House was also placed in lockdown, with Secret Service agents in tactical gear deploying around the building. The security alert was later partially lifted.

About half an hour after the incident began, the security lockdown at the Capitol was lifted and the doors reopened.