Four Iraqis have been killed in a suicide bomb attack on an office of the Patriotic Union of Kurdistan (PUK) in the northern Iraqi city of Mosul. The PUK is Iraqi President Jalal Talabani's political party. Police officials have warned that the death toll could climb as rescuers search the rubble. More than 30 people were injured in the attack. Mosul is a religiously and ethnically mixed city 390km (240 miles) north Of the capital, Baghdad.