Two civilians were killed and another four injured when a mortar shell fell on houses near a US military base in Mahmoudiya 30 kilometres south of Baghdad on Friday, Iraqi police said, according to DPA. The police said the US military sealed off the region in search of the assailants. In Kut, 170 kilometres south of Baghdad, one civilian was killed and another four injured on a roadside bomb explosion. In Fallujah, west of Baghdad, the police said the US army had arrested 11 civilians after a US military convoy came under missile attack.