Obama inauguration: President sworn in for second term
Barack Obama has taken the oath of office in Washington DC to inaugurate his second term as US president, before hundreds of thousands of spectators.
Mr Obama, 51, who is the 44th president of the US, was sworn in by Chief Justice John Roberts.
Monday's inaugural festivities in the US capital include black-tie balls, a parade and musical performances.
He was formally sworn in at a small White House ceremony on Sunday - the US Constitution dictates presidential terms begin on 20 January.