In retaliation, American troops backed by Bradley fighting vehicles swept through Iraqi neighborhoods before dawn Saturday, blasting houses suspected of being insurgent hideouts with machine guns and heavy weapons fire.
"This is to remind the town that we have teeth and claws and we will use them," said Lt. Col. Steven Russell, commander of the 1st Battalion, 22nd Infantry Regiment.
The U.S. death toll for the week climbed to 31, including those aboard the Black Hawk. Two other soldiers were killed near Mosul, raising concerns that the insurgency was spreading north.
The Black Hawk crashed on an island in the Tigris River and burst into flames — the third crash caused by hostile fire in two weeks and the second causing fatalities. Maj. Josslyn Aberle said the cause of Friday's crash had not been determined, but several other officers, speaking on condition of anonymity, believed it was shot down.
The helicopter, assigned to the 101st Airborne Division, went down about 9:40 a.m. about a half mile from the U.S. base in Saddam Hussein's former palace, which serves as headquarters for the 4th Infantry Division.
In Mosul, 250 miles north of Baghdad, guerrillas attacked a convoy with rocket-propelled grenades and small-arms fire Friday. The military said one U.S. soldier died and six others were wounded in the clash. Another soldier died in Mosul the night before when a homemade bomb exploded, the military said Friday.
Both of those soldiers, as well as the Black Hawk's four-man crew, were from the 101st Airborne Division, based at Fort Campbell, Ky.
In other developments:
Aberle said the command was reviewing security in and around Tikrit. Those measures were relaxed last month with the advent of the Muslim holy month of Ramadan. But "in view of the events this morning, with the helicopter going down, we are going to relook at our security measures and reinstating curfew is one of those options that's being considered," she added.
White smoke could be seen rising from the crash site on the east bank of the Tigris River as three other helicopters circled overhead. More helicopters could be seen hours later flying over a hilltop village on the west bank of the river.
Separately, guerrillas attacked a convoy in the eastern part of Mosul, 250 miles north of Baghdad, with rocket-propelled grenades and small-arms fire Friday morning. The military said one U.S. soldier died and six others were wounded in the clash.
Three others were injured later in the day when a roadside bomb exploded near the Mosul Hotel, which is now used as a military barracks, the military said. A military statement released Friday said a soldier died the day before near Mosul when a homemade bomb exploded.
The U.S. military said that the number of daily attacks on coalition forces dropped to 29 last week from a spike of 37 the week before.
The spate of attacks in the past week in Mosul, Iraq's third-largest city, has raised concerns among U.S. military commanders that the insurgency is spreading into that region from its main stronghold in the so-called Sunni Triangle, to the west and north of Baghdad.
The city is close to the semiautonomous Kurdish areas that lie between it and the Turkish border.
In Baghdad, about 500 people marched toward coalition headquarters to protest the arrest of 36 clerics in the past couple of months. They chanted Islamic slogans including "America's army will be wiped out," and "America is the enemy of God." They also carried a large banner reading "Prisons…will never terrify us."
Near Karbala, 70 miles south of Baghdad, the Polish brigade serving as part of the U.S.-led coalition held a memorial service for Maj. Hieronim Kupczyk who was killed in an ambush Thursday -- the first combat death for Poland.