Insurgents fired mortar rounds and rocket-propelled grenades at American troops in several attacks early Thursday, but the U.S. military said it had no details on casualties or damage.

Spc. Giovanni Lorente (search), a military spokesman in Baghdad (search), said U.S. troops in Tikrit (search), 120 miles north of Baghdad, came under an attack by rocket-propelled grenades. In the city of Ramadi, 60 miles west of the capital, three separate mortar attacks targeted U.S. troops.

Lorente said a U.S. logistics base in Balad (search), a small town north of the capital near the city of Tikrit, also came under mortar attack.

Tikrit, Saddam Hussein's hometown, together with Ramadi and Balad, are part of the so-called "Sunni triangle," a swath of land west and north of Baghdad across the Euphrates and Tigris rivers that has been the scene of almost daily attacks on U.S. occupation forces. The area is known to be a stronghold of Saddam supporters, although many residents deny that the former dictator still enjoys a following among them.

Capt. Michael Calvert, a spokesman for the 3rd Armored Cavalry Regiment, which is responsible for Ramadi, said the regiment's base in a former Saddam palace by the Euphrates River received a mortar round on Wednesday night.

He said he knew of no casualties among troops on the base and it was not clear whether the attack was one of the three reported by Lorente.

Saddam's fate has been unknown since the overthrow of his regime in April. American officials are offering $25 million for information leading to the arrest of Saddam, and $15 million for each of his sons.

U.S. officials acknowledge that his uncertain fate has helped fuel a growing insurgency that has hampered their efforts to re-establish security and get vital services like electricity and water back on line. Pro-Saddam loyalists have been blamed for frequent acts of sabotage on the nation's infrastructure, as well as frequent attacks on U.S. soldiers.

The military, meanwhile, said it had seized several large weapons caches at checkpoints around the country.

The largest -- including 400 to 500 rocket-propelled grenades -- was found in a vehicle on Tuesday on a road between Ramadi and Asad, west of the capital. The military said it had conducted more than 2,000 patrols and arrested 213 suspects since Tuesday. Most were suspected of common crimes, though some were wanted on murder charges.

The U.S.-led government announced it would begin recruiting members of a new Iraqi army on July 19. Maj. Gen. Paul Eaton, in charge of training the new army, said the coalition hoped to have 1,000 soldiers training by August, and 12,000 by the end of the year. They hope to have 40,000 by an unspecified date in 2004.

Establishing an Iraqi army and police is a main goal of the U.S.-led provisional government, which hopes the Iraqi forces will be able to take over at least some of the security needs of the country.

In Washington, Defense Secretary Donald H. Rumsfeld said Wednesday that the U.S. Army's 3rd Infantry Division, which played a central role in capturing Baghdad in April, is beginning to withdraw from Iraq, and will be back in the United States by September.

He did not say whether the troops would be replaced by another U.S. unit, although he said he expects thousands of international soldiers to begin operating in Iraq by late summer or early fall.

Also Wednesday, a committee of female Iraqi academics, political activists and sociologists demanded a minimum of 30 percent representation for women in future city councils and the national government. The group, which calls itself the Voice of the Women of Iraq, also said it wanted greater rights and freedoms for women.