A double truck bombing tore through the village of a small Shiite ethnic minority near the northern Iraqi city of Mosul, while nine blasts wracked Baghdad in a wave of violence Monday that killed at least 48 people and wounded more than 250, Iraqi officials said.
The attacks provided a grim example of U.S. military warnings that insurgents are targeting Shiites in an effort to re-ignite the kind of sectarian violence that nearly tore the country apart in 2006 and 2007.
The U.S. military has stressed that despite the rise in attacks, the Shiites are showing restraint and not retaliating as they did more than two years ago when a similar series of attacks and bombings provoked a Shiite backlash that degenerated into a sectarian slaughter claiming tens of thousands of lives.
The deadliest blast on Monday was a double truck bombing in Khazna village, just east of Mosul, home of the Shabak, a small Shiite ethnic group in the north.
The Shabak, who have their own distinct language and belief system, are part of the mosaic of ethnic and religious minorities in Iraq's north that include Yazidis, Assyrian Christians, Turkomen Shiites and Kurds - all of whom have been targeted in the past by Sunni Arab insurgents.
The two explosives-laden trucks went off nearly simultaneously and less than 500 yards (meters) apart, killing at least 28 people and wounding 138, said police and hospital officials.
The U.S. military confirmed at least 25 were killed.
No one has claimed responsibility for the attack, but it bore the hallmarks of al Qaeda in Iraq and other Sunni insurgents who remain active in Mosul and surrounding areas.
Witnesses described a chaotic scene of rescuers searching through the rubble of at least 15 houses that were destroyed. Many of the dead and wounded were sleeping on their roofs because of the summer heat.
The explosions left a 7-foot (2 meter) crater and reduced the houses to piles of bricks, twisted metal and smoking debris.
"If we had slept inside, we would have been killed," said Mahmoud Hussein, 28, who was sleeping on his roof some 150 yards (meters) away when the blast occurred.
Qusay Abbas, who represents the Shabak minority as a member of the Ninevah provincial council, blamed security forces for failing to protect the area on the eastern outskirts of Mosul, which the U.S. has called the last stronghold of al Qaeda in Iraq.
The village was a relatively easy target because it lacked many of the security measures prevalent in larger cities. A similar attack by a suicide truck bomber against a small Turkomen Shiite village on Friday flattened a mosque and killed 44.
A string of nine bombs also went off across Baghdad despite the security gains there that have prompted the Iraqi government to order the removal of nearly all the blast walls in the city over the next 40 days.
The first bomb was hidden in a pile of trash that exploded about 5:50 a.m. near a group of day laborers drinking tea in the religiously mixed neighborhood of Amil, killing at least seven and wounding 46, officials said.
About 10 minutes later a car bomb targeted construction workers in western Baghdad, killed another 10 people and wounded 35, according to police.
A few hours afterwards, a roadside bomb exploded in front of a mosque in the primarily Sunni neighborhood of Sadiyah in southwest Baghdad, killing two and wounding 14 others, a police official said.
A minibus exploded in the Shiite Shula neighborhood in northwest Baghdad, killing one and wounding three more, said police.
Five other bombs went off in various spots around the city throughout the day, wounding a total of 11 other people.
All the officials spoke on condition of anonymity because they weren't authorized to release the information.
American commanders have warned of increased violence in advance of January's national elections, which would likely hurt Prime Minister Nouri al-Maliki's re-election chances.
Al-Maliki condemned the attacks Monday and told Defense Ministry officials they must hunt down the insurgents.
"Using all of your capabilities, you will chase the terrorist cells so they can no longer find a safe place to put together their plans or be able to carry them out," he said during a conference in Baghdad.
The attacks have raised concerns about the ability of Iraqi security forces to contain violence as U.S. combat troops wind down duties as part of a withdrawal plan that would see all American forces out of Iraq by the end of 2011.
Al-Maliki and other lawmakers have repeatedly said Iraq's security forces are able to deal with the violence.
Meanwhile, the brother of an Australian contractor killed in Baghdad's protected Green Zone told reporters that his family was "terribly distraught."
Iraqi authorities have arrested Daniel Fitzsimmons, a British contractor, over the shooting deaths of Paul McGuigan of Britain and Darren Hoare of Australia. Fitzsimmons could be the first Westerner to face an Iraqi trial on murder charges since a U.S.-Iraqi security pact lifted immunity once enjoyed by foreign contractors.
"No one wants to think the worst, do they?" Rodney Hoare told reporters in Brisbane, Australia, on Monday. "It's such a tragedy and everyone's hurting deeply."