BAGHDAD -- Three Iraqi civilians were killed and a child critically injured when American soldiers stormed a small home north of Baghdad, the U.S. military said yesterday.

The soldiers were pursuing members of a suicide bombing network near Tikrit when they entered the home late Monday and came under fire, the military said in a statement.

The Iraqi victims - farmer Ali Hamed Shihab; his wife, Naeema Ali; and their son, Dhiaa Ali, 18 - were killed in the crossfire when the U.S. soldiers returned fire, officials said.

"We sincerely regret when civilians are injured during our operations, and we make every effort to protect them," said Maj. Winfield Danielson.

It was the second incident in recent days in which Iraqi civilians were killed mistakenly during operations by U.S. forces. An errant helicopter strike Saturday killed six civilians and three guards allied with U.S. troops.

"I was shocked when I saw their bodies, and I started to shiver," said Muhammad Ismail Shihab, whose aunt, uncle and cousin were killed in Monday's raid. "All of them were near their beds. The Americans are liars when they said my family was killed because the soldiers came under fire."

One of the surviving guards, a relative of one of the men killed in the helicopter airstrike, said yesterday that he did not know why an Apache helicopter mistook the U.S.-allied Concerned Local Citizens checkpoint for an enemy safe house.

"In the meantime, we are continuing our duties just like before, and all of our operations are under way, but our voices must be heard. If they don't have an immediate investigation to determine what happened, we will withdraw from the Concerned Local Citizens," said Mezahim Radam, whose uncle was killed Saturday.

Garrett Therolf and Raheem Salman write for the Los Angeles Times.