A woman driver was shot and killed by US police after trying to ram through a White House barricade with a young child in the car.

The Boston Marathon bombing suspects had some training in carrying out their attack, according to the chairman of the US House Homeland Security Committee.

The Boston marathon bombs were explosives packed in 6-litre pressure cookers and placed in black duffel bags, according to a source close to the investigation.

US President Barack Obama has said they do not know who carried out the Boston marathon bombings or why.

Police and the FBI have raided a number of homes in Boston in the hunt for those responsible for the explosions at the Boston Marathon.

The full might of America's police and security services was today focused on finding out who planted the Boston Marathon bombs, and why.

The White House today acknowledged public frustration with the Iraq war but tried to play down Republican anxieties as the House of Representatives prepared to pass legislation that could cut off funding for US troops as early as July.

Bogus claimants spent up to $1.4bn meant for hurricane victims on tropical holidays, champagne, a divorce lawyer and even a sex change, investigators in the United States have revealed.