Iraq chases Baghdad sleeper cells as 'Zero Hour' looms over capital

BAGHDAD (Reuters) - Iraqi insurgents are preparing for an assault on Baghdad, with sleeper cells planted inside the capital to rise up at "Zero Hour" and aid fighters pushing in from the outskirts, according to senior Iraqi and U.S. security officials.

Sunni fighters have seized wide swathes of the north and west of the country in a three week lightning advance and say they are bearing down on the capital, a city of 7 million people still scarred by the intense street fighting between its Sunni and Shi'ite neighbourhoods during U.S. occupation.