Updated

A mortar attack killed two American soldiers and wounded four others Friday at an outpost north of Baghdad (search), and a third American died in a gunbattle in the northern city of Mosul, the U.S. military said.

The mortar attack occurred about noon at a 4th Infantry Division (search) forward operating base near Samara, 70 miles north of Baghdad, the U.S. Central Command said.

It was the second mortar attack against a 4th Infantry Division position in as many days. Late Thursday, 13 soldiers from the division were wounded when a mortar struck a hangar at the U.S. Camp War Horse near Baqouba, 40 miles northeast of Baghdad.

The 4th Infantry is responsible for security in a large swath of territory in northern Iraq and has suffered more attacks than any other U.S. command in Iraq, according to American officials in Baghdad.

In Mosul, a soldier from the 101st Airborne Division (search) was killed during a gunbattle before dawn Friday with armed men who attacked a grain storage facility, the military said.

Since President Bush declared an end to major combat in Iraq on May 1, 108 U.S. soldiers have been killed by hostile fire.

In Fallujah (search), a center of Sunni Muslim resistance 40 miles west of Baghdad, U.S. soldiers were seen beating and kicking a pair of suspects detained after what witnesses said was a roadside bombing. It was the sixth attack by insurgents in Fallujah in as many days.

Iraqi witnesses said the attack took place near a bridge at the western end of Fallujah. The witnesses said three injured U.S. soldiers were evacuated after American soldiers raked the area with gunfire.

After the attack, television footage showed U.S. troops detaining several Iraqi civilians, with one soldier dragging a man from his vehicle and punching him repeatedly in the abdomen as he fell to the ground. Another soldier could be seen kicking a detainee in the leg before hauling him from the pavement and leading him away.

Elsewhere, police said two children — aged 3 and 8 — were killed and three adults wounded in a grenade attack on a police station in Mosul, a city that had been relatively quiet for weeks.

In another incident near Baqouba, an American patrol was attacked by rocket-propelled grenades and small-arms fire Thursday night, U.S. officials said. The Americans pursued the two Iraqi attackers into a house and killed them, the military said.

Also Thursday, 4th Infantry troops detained six men digging by a roadside near Beiji, 120 miles north of Baghdad, with the intention to place bombs there.

In a videotape delivered to Associated Press Television News, a heretofore unknown group — Ansar Saddam al-Jihadiya (search) or Saddam's Jihad Supporters — claimed responsibility for attacks on Americans. The tape showed three men — their faces covered — holding a weapon and a picture of the ousted leader.

"Our organization, with the help of God, has carried out attacks on many American targets and a number of local traitors and agents," one of the three said. "These operations will continue until the atheist army will leave Iraq."

In Baghdad, at least two Iraqis were killed and seven wounded when rockets fell on the Ad-Doura neighborhood late Thursday, residents said. The rockets smashed into several market stalls and damaged a power plant.

"About 10 p.m. we heard the sound of explosions," said Odai Abdul Rahman, a baker. "We came out of the bakery and saw some destroyed shacks and injured people lying on the ground."

Lt. Col. George Krivo, the U.S. command spokesman, said attacks on coalition forces have averaged about 26 a day over the past two weeks. About three-quarters of the attacks have occurred in an arc stretching from the west through Baghdad to the region north of the capital.

U.S. Deputy Defense Secretary Paul Wolfowitz (search) referred indirectly to the increased military activity, telling reporters on his arrival in Baghdad on Friday that American forces are "taking the fight to the enemy," whose goal is to "take Iraq back to the prison of tyranny from which they've finally been liberated."

In southern Iraq, firebrand Shiite Muslim cleric Muqtada al-Sadr (search) lashed out at the U.S.-backed administration, accusing it of oppressing religious leaders in a manner reminiscent of Saddam Hussein.

During a sermon Friday at a mosque in the southern town of Kufra, the cleric claimed that the new regime was little different from the old — a view not universally shared among his fellow Shiites.

"The current regime is the same, and there are many parties which cooperate with the new regime," he said. "I feel sorry about this. They attack Islamic scholars. We denounce these attacks and we totally reject them."

U.S. officials have warned they may crack down on al-Sadr because of his armed force, al-Mahdi's Army, which brandishes weapons in strongholds such as the Sadr City area of eastern Baghdad.