Three suicide attacks, including one by a bomber who rode in an ambulance to hospital before blowing himself up, killed 33 people in central Iraq on Wednesday, just days before nationwide elections.
The blasts in Baquba, the deadliest to hit the country in nearly a month, also wounded 55 people and spurred security forces to clamp an immediate curfew on the city, 60 kilometres north of Baghdad.
At least 10 policemen were among the 33 dead, a security official said.
The attacks came despite heightened security across Iraq ahead of Sunday's vote and after the leader of al-Qaeda in Iraq (AQI), Abu Omar al-Baghdadi, threatened to disrupt the election by "military means".
Two near-simultaneous suicide vehicle bombs ripped through the provincial housing department's offices and a nearby traffic intersection at around 9.30 a.m. (0630 GMT), the security official from Baquba operations command said.
A bomber in police uniform then rode with wounded victims in an ambulance to the hospital where he blew himself up, according to Major Ghaleb al-Juburi, Baquba police spokesman.
"The suicide bomber tried to blow himself up against the police chief when he came to see the wounded in the hospital," said the security official, on condition of anonymity.
Police chief Major General Abdul Hussein al-Shimmari escaped unharmed but members of his personal security team, including Colonel Nabil Ibrahim, were wounded. Diyala provincial health chief Dr Ali al-Timimi was also hurt.
"Just a few minutes after we began receiving victims, the police chief arrived," said policeman Hassan Timimi, who was in the hospital when it was bombed and suffered wounds to a leg.
"We were surprised by a new attack, something went off. I was carrying a wounded person, trying to take him to the emergency room, but the bomb went off in the main gate of the emergency room and I was knocked unconscious."
An advisor to Prime Minister Nuri al-Maliki, Ali al-Mussawi, blamed the attacks on "terrorists" bent on disrupting Sunday's vote.
"They want to cause confusion and stop the people from voting because the elections are a big threat to terrorists," he said. "They have put all their efforts into jeopardising the elections."
The first vehicle in Wednesday's attacks crashed through the entrance to the provincial housing department's compound, which sits next to a police station, before exploding.
Moments later at a nearby traffic intersection, a suicide bomber triggered the explosives packed into his vehicle, creating a powerful blast.
"I was going to the market, passing through the intersection," Ali Ehsan Ibrahim, who suffered head wounds in the attacks, told AFP from Baquba's hospital.
"Before I reached it, I saw an explosion near the police station and after that, traffic was jammed and people tried to flee. "The second attack happened near me - I did not feel anything and I ended up in the hospital."
US and Iraqi security forces have cordoned off the hospital, an AFP journalist at the scene said.
A security official at Baquba operations command later said that police defused two car bombs in the city centre. Two other bombs had also been found hidden in television sets.