BAGHDAD A tractor-trailer loaded with Shiite militia rockets accidentally exploded Wednesday in a densely populated area of northeast Baghdad, killing 18 people and wounding 75, the U.S. military said. It was the deadliest explosion in Baghdad in more than two months.
Iraqi police said the blast was a suicide truck bomb that struck near the home of an Iraqi police general, killing his nephew and wounding his elderly parents.
But the U.S. military said Shiite extremists were positioning a large truck of loaded with rockets and mortars, aiming the weapons at a U.S. combat outpost 700 yards away, when it mistakenly exploded.
"They were trying to attack us at that FOB (forwarding operating base), and it went off (accidentally). They wouldn't waste rockets like that," said Lt. Col. Steve Stover, a U.S. military spokesman.
Stover said the militants responsible for the truck had likely fled recent fighting in Sadr City.
The explosion crumbled several two-story buildings, buried cars under rubble and sheared off a corrugated steel roof.
Also Wednesday, three U.S. soldiers were shot dead in northern Iraq, and the decaying bodies of at least 23 Iraqis were discovered in a shallow grave and a sewer shaft at separate sites near Baghdad.
The Americans were killed when gunmen opened fire on them in the northern Iraqi village of Hawija, according to a brief military statement.
The area, once a hub for Sunni militants and disaffected allies of Saddam Hussein, is thought to have been pacified in recent months. Last year it hosted one of the largest sign-on ceremonies for tribal sheiks partnering with U.S. forces to fight al-Qaida in Iraq.
The latest U.S. deaths brought to at least 4,090 the number of U.S. military personnel who have died in the Iraq war since it began in March 2003, according to an Associated Press count.
South of Baghdad, Iraqi villagers and soldiers unearthed at least 13 bodies from a shallow, dusty grave in farmland on the outskirts of Latifiyah, a mostly Sunni town that also has some Shiite residents. The bodies were first discovered Tuesday, but digging continued a day later.
Associated Press Television News footage showed Iraqi troops and civilians clawing through dusty soil with shovels. At least three severely decomposed bodies could be seen in side-by-side graves.
The U.S. military could not confirm the discovery, but said its soldiers, acting on a tip from a local citizen, found at least 10 decomposed bodies Tuesday in a separate location, in the sewer shaft of a building in east Baghdad.
Those victims appeared to have died more than two years ago, Stover said, adding that Iraqi police have taken over the investigation.
Latifiyah, which lies about 20 miles south of Baghdad, was taken over by al-Qaida-linked militants a few years ago, and became a hotbed of Sunni militant activity before U.S. and Iraqi forces regained control late last year, said Iraqi Maj. Faisal Ali Hussein, who supervised that digging Tuesday.
Only now are villagers feeling safer without the militants there beginning to point out possible sites of mass graves in the area, he said.
Most of the bodies were too decomposed to identify and they were reburied next to where they were discovered, said another Iraqi army officer at the scene, who refused to give his name because of safety concerns.
Meanwhile, the U.S. military said it detained nine suspects and destroyed two "terrorist safe houses" Wednesday in raids targeting al-Qaida in Iraq across central and northern parts of the country.
One of the men had been wanted for alleged involvement in weapons distribution and car bombings in Baghdad, the military said in a statement.
Another suspect was responsible for organizing suicide bombings and helping foreign militants enter Iraq, the statement said.
Information from other detainees already in U.S. custody led American troops on Wednesday to two facilities that housed foreign militants west of Mosul, it said. The buildings were safely destroyed.
In a separate operation Wednesday, Iraqi police said they uncovered a large weapons cache near Samarra, 60 miles north of Baghdad.Among the load were hundreds of explosive belts, three assembled car bombs and several different types of rockets, an officer said on condition of anonymity because he was not authorized to release the information. One suspect also was arrested in the raid.
Associated Press writers Bushra Juhi, Sameer N. Yacoub and Lauren Frayer contributed to this report.