BAGHDAD A suicide bomber on a bicycle killed 30 Iraqi policemen doing their morning exercises at a base north of Baghdad on Monday, in one of the deadliest strikes on security forces in months.
And a roadside bomb attack in Baghdad wounded a U.S. general -- the highest ranking U.S. officer to be wounded in Iraq since the invasion in 2003.
The suicide bombing north of Baghdad targeted a police rapid reaction force at their base in volatile Diyala province, said Major-General Ghanim al-Quraishi, the Diyala police chief.
A shopkeeper whose store is close to the base told Reuters he had seen a man riding a bicycle slip through a gap in the concrete wall surrounding the compound and heard a huge blast seconds later that threw a cloud of dust into the air.
"I saw many bodies covered in blood. Some were dying, some had arms and legs blown off," said store owner Ali Shahine.
At least 20 people were wounded in the attack, including a woman and a child, police said. Hospital officials gave the same number of casualties.
No group claimed responsibility for the bombing, but it bore the hallmarks of al Qaeda, which has often used suicide bombers to devastating effect in attacks on Iraqi security forces.
The base is in the city of Baquba, capital of Diyala province, a religiously and ethnically mixed region where al Qaeda and other Sunni Arab insurgent groups as well as Shi'ite Muslim militias operate.
Also in Diyala, police found 20 decapitated bodies on Monday, dumped near a police station west of Baquba. The identity of the victims was not immediately known. Beheadings in Iraq are usually the work of al Qaeda militants.
Eleven Sunni and Shi'ite tribal leaders, members of an anti-al Qaeda group in Diyala, were kidnapped on Sunday on their way home after meeting a representative of the prime minister in Baghdad. The Defence Ministry said eight were rescued on Monday when soldiers raided the house where they were held.
The ministry said another raid was under way to try to find the three tribal sheikhs still missing. But two Diyala government officials said one of those missing, Sunni sheikh Modher al-Azzawi, was found dead earlier on Monday.
U.S. forces blamed a former commander in radical Shi'ite cleric Moqtada al-Sadr's Mehdi Army militia for the kidnapping.
In other violence, a car bomb in a residential area in the northern Iraqi town of Siniya demolished two homes, killing eight people and wounding 13, police said.
And Brigadier General Jeffrey Dorko, commanding general of the Gulf Region Division of the U.S. Army Corps of Engineers, was wounded along with another soldier when a roadside bomb exploded beside their convoy, the U.S. military said. His wounds were not life-threatening and he was evacuated from Iraq.
The U.S. military handed over security control for Kerbala province, home to one of the holiest cities in Shi'ite Islam, to the local authorities on Monday. It was the eighth of Iraq's 18 provinces to be transferred to Iraqi control.
The top U.S. civilian and military officials in Iraq, Ambassador Ryan Crocker and General David Petraeus, said it was a significant moment in Iraq's transition to self-reliance.
Kerbala, the provincial capital and a centre of Shi'ite pilgrimage and worship, has been largely peaceful, except in August when tension between local factions in the holy city boiled over during a major festival and 52 people were killed.
The U.S. military has poured 30,000 extra troops into Iraq as part of President George W. Bush's new strategy to quell an explosion of sectarian violence that erupted after the bombing of a revered Shi'ite shrine in Samarra in February 2006.
Al Qaeda has vowed to step up attacks on the security forces as well as Sunni Arab tribal leaders and Sunni insurgents who have allied themselves with U.S. forces in Diyala, one of Iraq's most dangerous provinces, to root out the Sunni Islamist group.
U.S. and Iraqi forces launched a major offensive against al Qaeda in Diyala in June, regaining control of Baquba and forcing many of the group's fighters to flee northwards, to Salahuddin and Nineveh provinces, to regroup.
But U.S. commanders say al Qaeda is resilient and retains a small presence in Diyala.
Baquba's police chief was among 26 people killed last month when a suicide bomber blew himself up in a mosque compound as local Shi'ite and Sunni Arab leaders held reconciliation talks.
(Additional reporting by Aseel Kami in Baghdad)