Gunmen have staged a mass kidnapping at the Iraqi office of the Red Crescent humanitarian agency in Baghdad.

The assailants captured dozens of employees but left the women behind, an aid official told AP news agency.

The gunmen are believed to have been wearing police or military uniforms and arrived in a number of pick-up trucks.

It is the latest in a wave of kidnappings and comes as the UK Prime Minister Tony Blair makes a surprise visit to the Iraqi capital.