IN a video sold in Baghdad's souks, a group of women draped in cartridge belts and clutching pistols and rifles explained why they had taken up arms against the US military in Iraq. “We are defending Islam and its sanctity. This is the country we were raised in. Why should we stand by while our men are defending the country?” said one woman, her face covered. “What's stopping women?” Lately, nothing is stopping them. Even as overall violence in Iraq has fallen to levels unseen since early 2004, there has been a dramatic rise in the number of attacks by women, deployed by Sunni Arab militants as suicide bombers. There have been 23 suicide bomb attacks carried out by women in Iraq so far this year, compared to eight attacks for the whole of 2007, the US military says. Last week, on July 28, three women wearing explosive vests mingled with Shi'ite religious pilgrims in Baghdad and blew themselves up. A fourth bomber, also believed to have been a woman, struck Kurds protesting against a disputed election law in the north of the country. In all, they killed nearly 60 people in the deadliest single day in Iraq for months. Nearly 250 people were wounded. Analysts say many women are motivated by a thirst for revenge for family members killed or captured. Others may be determined to show that they are as committed to the cause as any man. In parts of Iraq, there is no shortage of desperate women with a grudge against US and Iraqi forces. Outside a police station in the city of Baquba, capital of Diyala, the province where most female suicide attacks have taken place in recent months, women waited for news of detained male relatives. “The Americans took my husband. They destroyed our home. We've got nothing. We're living by the grace of God. We will not stay silent, and everything, including bombings, we can do in response,” said one enraged woman who declined to be named. US and Iraqi forces have routed Al-Qaeda in Baghdad and Western Iraq, and the Sunni Islamist group has since regrouped in Iraq's north, including Diyala, where a major security operation is underway to crush insurgents. As more male members of insurgent groups are killed or captured, more women may want retribution. “Violence by US or Iraqi forces will lead in many cases to grudges and a wish to take revenge, especially when husbands are killed. I think this is one of the main reasons for female bomb attacks,” said Henaa Edwar, head of Iraqi women's group Amal. Seja Aziz, a member of the security committee of Diyala's provincial council, said some women and girls are driven into the arms of Al-Qaeda by families embroiled in the insurgency. The US military says many of the female suicide bombers are victims of rape, a claim that is difficult to verify. The military calls the use of female bombers a desperate tactic by foes on the retreat, and says it shows the difficulty militants now face recruiting the young foreign Arab men they once trafficked into Iraq by the score for suicide missions. Increased border security has made it more difficult to smuggle foreign fighters into Iraq, while a decision by Sunni Arab tribal leaders to turn on Al-Qaeda has helped to deprive the group of refuge and Iraqi volunteers. Female suicide bombers offer tactical advantages for the militants. Explosives are easy to hide under the voluminous black robes worn by many Iraqi women, and Arab cultural norms mean male guards are less likely to search them thoroughly. “Female suicide bombers cost little, provide ease of planning and are relatively free of risk to terror organizations. There is little chance that security forces will obtain sensitive information from them,” said US military spokesman Major John Hall. The insurgents are not the only side seeking to take advantage of women's determination to join men in the fight. Iraq's security forces have set up the “Daughters of Iraq” program training women to search other women at checkpoints. “We hope that more women will join us in this work,” said Rana Abid, a female guard at a checkpoint in Diyala province. “We are helping our brothers to protect the new Iraq.”