BAGHDAD- A Black Hawk helicopter went down Wednesday in northern Iraq, killing all 14 U.S. soldiers aboard, the military said, the deadliest crash since January 2005.
Prime Minister Nouri al-Maliki, meanwhile, lashed out at American criticism a day after President Bush expressed frustration with the Iraqi government's inability to bridge political divisions.
"No one has the right to place timetables on the Iraq government. It was elected by its people," the Shiite leader said at a news conference in Damascus at the end of a three-day visit to Syria.
"Those who make such statements are bothered by our visit to Syria. We will pay no attention. We care for our people and our constitution and can find friends elsewhere," al-Maliki said.
The military said initial indications showed the UH-60 helicopter experienced a mechanical problem and was not brought down by hostile fire, but the cause of the crash was still under investigation.
It was one of two helicopters on a nighttime operation. The four crew members and 10 passengers who perished were assigned to Task Force Lightning, the military said. It did not release identities pending notification of relatives.
The U.S. military relies heavily on helicopters to avoid the threat of ambushes and roadside bombs - the deadliest weapon in the militants' arsenal - and dozens have crashed in accidents or been shot down.
The deadliest crash occurred on Jan. 26, 2005, when a CH-53 Sea Stallion transport helicopter went down in a sandstorm in western Iraq, killing 31 U.S. troops.
A U.S. soldier also was killed and three others were wounded Wednesday during fighting west of Baghdad, the military said separately.
Wednesday's deaths raised to at least 3,722 members of the U.S. military who have died since the Iraq war started in March 2003, according to an Associated Press count.
Elsewhere in northern Iraq, a suicide truck bomber targeted a police agency in northern Iraq, killing at least 27 people and wounding 65, police and hospital officials said.
The attack occurred just before noon in Beiji, 155 miles north of Baghdad, according to the officials, who said those killed included 18 policemen and nine civilians, while 20 officers and 45 civilians were wounded.
Brig. Gen. Kevin Bergner, a U.S. military spokesman in Baghdad, said the attack bore all the hallmarks of al-Qaida in Iraq, including the use of a suicide bomber and the high number of civilian casualties.
"It appears to be something that is consistent with an al-Qaida-related attack," he told AP Radio in an interview.
Iraqi police and soldiers have frequently been targeted by militants seeking to disrupt U.S.-led efforts to enable the forces to take over their own security so foreign troops can go home.
Those killed Wednesday included 18 policemen and nine civilians, while 20 officers and 45 civilians were wounded, the officials said.
A bomb and small-arms attack against a security post shared by police and U.S. paratroopers also killed 13 Iraqi officers in Beiji in late June.
Jassim Saleh, 41, who lives about 500 yards from the blast site, said he saw an explosives-laden truck carrying stones strike the police station.
"It was a horrible scene. I can't describe it," he said. "The bodies were scattered everywhere. I was injured in my hand and a leg, but I took three wounded people to the hospital in my car."
Police said nine policemen and 10 civilians were killed, while 21 civilians and five officers were wounded.
A roadside bomb also targeted a police patrol in the center of Tikrit, Saddam Hussein's hometown 80 miles north of Baghdad, killing one officer and wounding another, along with two civilians, authorities said.
With violence unrelenting, political pressure mounted for al-Maliki to show progress in bringing Iraq's battling factions together.
Bush acknowledged his frustration with Iraqi leaders' inability to bridge political divisions on Tuesday, but said only the Iraqi people can decide whether to sideline the troubled prime minister.
"Clearly, the Iraqi government's got to do more," Bush said at the close of a two-day summit with the leaders of Mexico and Canada.
On Wednesday, however, Bush scrambled to show he had not abandoned al-Maliki, wary of how his comments the day before about the Iraqi leader had widely been interpreted.
"Prime Minister Maliki's a good guy, good man with a difficult job and I support him," Bush said in a speech to the Veterans of Foreign Wars conference.
"And it's not up to the politicians in Washington, D.C., to say whether he will remain in his position," Bush said. "It is up to the Iraqi people who now live in a democracy and not a dictatorship."
The Sept. 15 deadline for Bush's next progress report to Congress is fast approaching, leaving him little time to show that his U.S. troop buildup is succeeding in providing the enhanced security the Iraqi leaders need to forge a unified way forward.
Al-Maliki blamed the U.S. presidential campaign for the recent tough words from Bush and other American politicians.
Without naming any American official, al-Maliki said some of the criticism of him and his government was "discourteous."
U.S. Ambassador Ryan Crocker, co-author of the highly anticipated report to Congress, also said Tuesday that Washington's blueprint for reconciliation was insufficient to win back control of Iraq. Congressional benchmarks such as laws to share oil revenue and reform security services don't tell the whole story, he said.
Crocker, who will present the report with military commander Gen. David Petraeus, called Iraq's problems difficult but fixable, arguing for more time for his diplomacy and operations by the bolstered American military force.
"Failure to meet any of them (congressionally mandated benchmarks) does not mean the definitive failure of the state or the society," Crocker said. "Conversely, to make them all would not by any means mean that they've turned the corner and it's a sun-dappled upland from here on in with peace and harmony and background music. It's just a lot more complex than that."
He echoed Bush's frustration with the lack of action by al-Maliki government's on key legislative measures.
"Progress on national level issues has been extremely disappointing and frustrating to all concerned - to us, to Iraqis, to the Iraqi leadership itself," Crocker said. But he added that the Shiite prime minister was working "in the shadow of a huge national trauma."