US 'grieving and shocked' after shootings says Obama

President Obama says the US is "grieving and in shock" after the Arizona shootings which left six people dead and a congresswoman seriously wounded.

Flags across the US have flown at half mast and earlier the president led the nation in a minute's silence.

On the east steps of the Capitol building, hundreds of congressional staff also paid tribute to Ms Giffords and the other victims of Saturday's shooting.

In Tucson, small groups gathered in public spaces, in offices and in shops and stopped to observe a minute's silence.