Insurgents apparently shot down a U.S. Army reconnaissance helicopter in this northern city Friday, killing its two pilots, in the second fatal helicopter crash in Iraq in less than a week.

One witness said he heard machine-gun fire before the helicopter crashed, and children told soldiers that the sound of gunfire came from three or four directions and that the helicopter was flying erratically, possibly trying to evade it.

The helicopter looked like it crashed on a muddy plateau and then cartwheeled down a 25-foot embankment that was sloped at about a 45-degree angle. It came to rest near strewn garbage. The helicopter's two pilots — the only people aboard — were killed.

The pilot may have tried to land it in the dirt clearing, about 20 feet from some mud huts with clothes hanging along lines.

The crash came as Lt. Gen. John Vines, chief of the Multi-National Corps Iraq, predicted increased attacks around Iraq when final election results are released next week. At least 500 people and more than 50 U.S. troops have been killed since the Dec. 15 elections.

Vines, the second highest ranking general in Iraq, said from Baghdad's Camp Victory that there were indications the OH-58 Kiowa was shot down. "The indicators are that it was due to hostile fire," he said.

The armed helicopter was on a combat air patrol just outside Forward Operating Base Courage when it went down in Mosul, 225 miles northwest of Baghdad, the military said.

The crash deaths bring to at least 2,214 U.S. service members killed in Iraq since the beginning of the war in 2003, according to an Associated Press count.

Layth Shems al-Din said he was working in his butcher shop when he heard shots that he recognized from his service in the Iraqi army as coming from a heavy machine gun.

"At the same time, there was a helicopter hovering at a low level and after that I heard a strange sound from the helicopter, and then I heard the sound of a crash, but not an explosion," the 29-year-old told an Associated Press reporter by telephone.

He and Ayad Abdul Razzaq, a 35-year-old manager of a tourist agency, said the crash occurred as the helicopters flew over Mosul's al-Sukar neighborhood. They said the aircraft went down near the al-Sayegh mosque.

Razzaq said that after hearing the "strange sound, smoke came from the helicopter before it fell."

Maj. Richard Greene, executive officer of the 172nd Stryker Brigade's 2nd Battalion, 1st Infantry Regiment, said the helicopter "was responding to small arms fire being taken by Iraqi police."

Greene said the gunmen were not found.

Of reports the helicopter was shot down, Greene said: "I think I'd give that some credibility."

Army Lt. Joe Vanty, 32, of West Hartford, Conn., said it was "very credible" that the aircraft was shot down.

Vanty's platoon heard small arms fire and went toward the sound. The platoon came under fire from four directions and he said two helicopters were seen overhead. Shortly afterward, the soldiers were told one had gone down and they moved in that direction.

The helicopter crash came nearly a week after a Black Hawk helicopter carrying eight U.S. troops and four American civilians went down near the northern city of Tal Afar, killing all aboard. Pentagon officials said the cause of that crash was still being investigated, although bad weather was reported in the area at the time.

In Baqouba, a car bomb exploded near a police patrol, killing two officers and wounding six people, said Ahmed Hassan of the morgue in the city 35 miles northeast of Baghdad.

The U.S. military has predicted more violence for Iraq in the weeks ahead as the country's splintered politicians and religious groups struggle to form a government.

"We know the jihadists will attempt to attack the institutions of government probably when the results are announced to show their disdain for the democratic process," Vines told Pentagon reporters in a videoconference. "They think they have the right to impose their views on other Iraqis. So it's very likely that we would see violence as the results are announced."

While the last three days have been generally quiet, as the country observes the Islamic feast of sacrifice, Eid al-Adha, Vines said the insurgents "have not given up. They have not gone away. They have not gone home."

Final election results have been delayed by Sunni Arab complaints of fraud, but are expected next week. Although leading politicians have expressed hopes a government could be formed in February, most experts and officials agree it could take two to three months, as it did after the January 2005 elections for an interim government.

The governing United Iraqi Alliance, a Shiite religious bloc, has a strong lead, according to preliminary results. But it won't win enough seats in the 275-member parliament to avoid forming a coalition with Sunni Arab and Kurdish parties.

Sunni Arab politicians, meanwhile, expressed anger over remarks by Iraq's most powerful Shiite politician suggesting that the new constitution, approved in October, would not be amended.

A key Sunni Arab demand is weaker federalism and a stronger central government. The constitution now gives most power — including control over oil profits — to provincial governments. The Shiites in the south and the Kurds in the north control nearly all of Iraq's oil.