Baghdad ? A top U.S. commander said Saturday that two bombings carried out by women wrapped in bombs that killed nearly 100 people in Baghdad underscored that al-Qaida in Iraq remains a serious threat, but he vowed the military would “not give back any terrain” to the terror network.

Iraqis in Baghdad demanded more protection for markets, saying one of the bombers wasn’t searched because she was known as a local beggar and the male guards were reluctant to search women because of Islamic sensitivities.

U.S. and Iraqi officials said Saturday that pictures showed the bombers had Down syndrome and likely did not know they were being used in Friday’s attacks.

Ali Nassir, a 30-year-old day laborer whose hobby is raising birds, said people with disabilities often beg for food and money at the weekly al-Ghazl pet bazaar on Fridays.

“I saw the suicide bomber and she was begging,” Nassir said, adding the woman was known to the vendors. “The security guards did not search her because she is a woman and because it is not unusual to have beggars, mainly women and children, moving around in the market.”

Iraqi officials, who spoke on condition of anonymity, raised the death toll of Friday’s attacks to at least 99 – 62 people in the first blast at the central al-Ghazl bazaar and 37 others about 20 minutes later at the New Baghdad area pigeon market in southeastern Baghdad.

Unwitting attackers

Maj. Gen. Jeffery Hammond, the top U.S. commander in Baghdad, said the women appeared to be unwitting attackers.

“It appears the suicide bombers were not willing martyrs, they were used by al-Qaida for these horrific attacks,” he said. “These two women were likely used because they didn’t understand what was happening and they were less likely to be searched.”

He also reiterated military warnings that al-Qaida remains a serious threat despite major inroads against the network since the Americans began sending some 30,000 extra troops to the capital and surrounding areas in the spring.

“These two suicide vest attacks represent the worst of human nature,” Hammond said during a news conference. He said American forces would continue their targeted operations that have succeeded in decreasing attacks.

“We will not give back any terrain here in Baghdad,” he said.

Iraqi officials said they had pictures of the two women’s heads that were found at the scene that proved they had Down syndrome, and they said the explosives had been detonated by remote-control.

“This is very credible information,” said Lt. Gen. Abboud Qanbar, the chief Iraqi military commander in Baghdad, adding the photos would not be released to the public because of humanitarian concerns.

Lt. Col. Steve Stover, a military spokesman for the Baghdad area, said “they were both females and they both looked like they had Down syndrome.” Medical experts with his division had examined the photos and agreed the women probably suffered from the genetic disorder, he said.

A cell phone image of one of the heads viewed by The Associated Press was inconclusive.

‘A new low’

The U.S. military, which gave a lower combined death toll of 27, blamed the attacks on al-Qaida in Iraq and said they signaled a new desperation as concrete blast barriers and other security measures have stanched the group’s ability to stage deadly car bombings and similar attacks.

“It sounds like (al-Qaida in Iraq) has stooped to a new low where they’re using people who may not even know what they’re doing and strapped something to them and told them go into a market,” Stover said.

He said one of the women was carrying a backpack that was stuffed with ball bearings and shrapnel to maximize the casualties, while the other one was wearing an explosives vest.

The bombings served as a reminder that Iraqi insurgents are constantly shifting their strategies in attempts to unravel recent security gains around the country.

Friday’s blasts were the deadliest in the capital since an April 18 suicide car bombing that killed 116 and wounded 145.

Iraqi Prime Minister Nouri al-Maliki vowed to crack down on the militants.