Security increased

The two bridges over the Diyala River, a tributary of the Tigris, are commonly used by Shia pilgrims on their way to the holy Shia cities of Najaf and Kerbala to the south.

Last month, a truck bomb destroyed the Sarafiya Bridge in Baghdad, sending several cars crashing into the Tigris river.

Days later a suicide car bomber blew himself up on a ramp leading to another bridge in Baghdad.

As a result, city authorities banned trucks weighing more than 1.5 metric tonnes from all but two bridges across the river.