Bomb attacks in northeast Iraq kill 31, wound 48

Iraq's national poll on Sunday is viewed as pivotal for the war-scarred nation as U.S. troops prepare to end combat operations in August ahead of a full pullout by end-2011.

Police said the first two attackers drove explosives-packed cars at police stations in the centre and west of Baquba, 65 km (40 miles) northeast of Baghdad.

The third assailant, apparently wearing a police uniform and on foot, blew himself up in the grounds of the city's main hospital as the wounded were ferried there.

Baquba is the capital of Diyala, a troubled province where al Qaeda and other Sunni militant groups still battle U.S. troops and Iraqi security forces.

The governor's spokeswoman, Samira al-Shibli, said security forces had imposed a province-wide curfew and closed main roads at the entrances to big towns to try to prevent more attacks.

Sporadic political violence and assassinations have marred the immediate run-up to the election.

But until Wednesday the campaign had not witnessed major assaults by suicide bombers like those that devastated public buildings and hotels in Baghdad in January, December, October and August.

Many Iraqis fear bombers could strike again before the vote.

The sectarian slaughter unleashed after the 2003 U.S. invasion of Iraq has largely receded, but relations remain strained between once dominant Sunnis and the Shi'ite majority that was empowered by the fall of Sunni dictator Saddam Hussein.

(Writing by Alistair Lyon; Editing by Michael Christie and Jon Hemming)