A Black Hawk helicopter went down Wednesday in northern Iraq, killing all 14 US 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 US President George W. 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 US 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 US troops.