A gunman has reportedly killed several people, wounding up to 10 others, and is still on the loose at a US Navy centre in Washington.

A gunman has shot and wounded at least one person at a US Navy Yard in Washington DC.

America’s security chiefs have met to review the threat of a terrorist attack that led to the weekend closure of 21 US embassies and consulates in the Muslim world and a global travel warning.

State Police have warned residents that they will do a controlled explosion of items found in Norfolk Street in Cambridge where the Boston bombing suspects lived.

All Boston residents have been ordered to stay in their homes as the search for the surviving suspect in the marathon bombings continues after a night of violence that left the other suspect - reportedly his brother - dead.

US President Barack Obama called Boston mayor Tom Menino and Massachusetts governor Deval Patrick to offer federal assistance in responding to explosions that rocked the end of the Boston Marathon.