BAGHDAD, Iraq (CNN) -- Two mentally disabled women were strapped with explosives Friday and sent into busy Baghdad markets, where they were blown up by remote control, a top Iraqi government official said.

Iraqi soldiers secure the scene of a bombing Friday at a popular pet market in central Baghdad.

The bombs killed at least 98 people and wounded more than 200 at two popular pet markets on the holiest day of the week for Muslims, authorities said.

In both bombings, the attackers were mentally disabled women whose explosive belts were remotely detonated, Gen. Qasim Atta, spokesman for Baghdad's security plan, told state television.

Atta said the women were strapped with dynamite and ball bearings, citing members of the bomb squad. The explosives were detonated via cell phone, he said.

An Atta aide said that people referred to the bomber at central Baghdad's al-Ghazl market as the "crazy woman" and that the bomber at a second market had an unspecified birth disability.

The aide said authorities believe the women were unaware of plans to detonate the explosives. Watch how the use of the women represents a new tactic »

The nationalities and identities of the women have not been released.

U.S. military officials referred to the two attacks as suicide bombings, saying both women detonated the explosive devices.

The U.S. officials also gave a much lower casualty toll, with 27 civilians dead and 53 others wounded.

The Pentagon attributed the attacks to al Qaeda in Iraq and made no reference to the mental conditions of the women.

"By targeting innocent Iraqis, they show their true demonic character," said Lt. Col. Steve Stover, spokesman for the Multi-National Division-Baghdad.

"They care nothing for the Iraqi people; they want to subjugate them and forcefully create a greater Islamic sharia state," he said, referring to Islamic law.

The violence marked the bloodiest series of attacks in Baghdad since August, breaking a brief stretch of relative calm as attacks and deaths dropped after the 2007 increase in U.S. troop strength called the surge.

In Washington, U.S. Secretary of State Condoleezza Rice said the attacks show the reality of the continuing struggle against militants, adding that Iraqis have turned against "these terrible, violent people in their midst who will do anything."

"It certainly underscores and affirms the decision of the Iraqi people that there is no political program here that is acceptable to a civilized society, and that this is the most brutal and the most bankrupt of movements that would do this kind of thing," she said at a press briefing. "And I think that will underscore for the Iraqis, and it will make them tougher in the fight."

The first bomb blew up at al-Ghazl animal market around 10:30 a.m., killing 69 and wounding more than 140. The second blast happened about a half-hour later in the New Baghdad neighborhood pet market, killing 29 people and wounding 67.

Al-Ghazl pet market is a popular destination where people buy and sell cats, dogs, monkeys and other animals. Attackers have struck the market on Fridays -- its busiest day -- several times in the last year or so.

A January 2007 bombing killed 15 and wounded 52 at the pet market, and 13 people died and 58 were wounded in a November attack.

Other developments

A parked car exploded Thursday in a predominantly Shiite district in the Iraqi capital, killing five civilians and wounding eight others, the Interior Ministry said. The attack occurred after a string of roadside bombings that wounded 21 people, the ministry said.

Poland will withdraw its troops from Iraq by the end of October, a spokesman for the Polish military said Thursday. October 31 will be the last day of the Polish presence, Maj. Dariusz Kacperczyk said in Warsaw. About 900 Polish troops are in Iraq, with most in Diwaniya, some in Baghdad and others in the southern city of Kut. Twenty-two Polish troops have died during the nearly 5-year war in Iraq.

CNN's Ahmed Taha and Jomana Karadsheh contributed to this report.

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