A petrol station sits in ruins after a female suicide bomber blew herself up in Kano, Nigeria, last Thursday. On Monday two female suicide bombers blew themselves up at a trade show and a petrol station in Kano, killing one other person and injuring at least six others, police and a military source said. (Reuters)

There were four suicide bombing attacks by young women in Kano, Nigeria, last week. Especially worrying is that the reported ages of the suicide bombers are getting younger and younger.  A 10-year-old girl strapped with a suicide bomber’s explosives belt and her older sister were taken into police custody. The attacks raise concerns that Boko Haram has doubled its mobilization base.

These attacks and others led the city of Kano to ban public worship and celebrations of Eid, the holiday marking the end of Ramadan. Local police have issued warnings about women covered in hijab.

Who are the female suicide bombers in Kano?

Three narratives have emerged about who these young bombers were. A handful of reports originally suggested the women were among the Chibok girls kidnapped April 14 and other women and young girls abducted by Boko Haram over the past year. Another report instead alleges the young women are actually impoverished Kano beggars who have been outlawed by Kwankwaso. But a Nigeria-based security analyst says the suicide bombers are more likely to be the offspring of Boko Haram members.

The truth is we don’t know who these female bombers are, and we likely won’t anytime soon. In contrast to male suicide bombers, few female bombers leave “last will and testament” videos that could provide positive identification. What is clear is that regardless of whether the young women were girls abducted in Chibok or poor women picked up off the streets, Boko Haram has now embraced this tactical innovation quickly and with deadly results.

This is not a new phenomenon.

Nigerian scholars have echoed what I have claimed in my own research on women and terrorism — that female suicide bombers are not a new phenomenon, even in Africa. As early as December 2009, Al Shabaab began to disguise themselves as women in order to effectively carry out suicide-bomber targeted assassinations. Al Shabaab began to pair a male and female operative to give the appearance of a couple on a date. This was particularly effective when the group would attack soft targets like hotels, restaurants or markets.

Women have been involved in terrorism since the 19th century, but religious groups previously eschewed the use of female bombers. The innovation in tactics by these groups introduces new challenges to those defending against terrorism. As scholar Nojeem Shobo of the University of Lagos has said, including women as perpetrators in terrorist attacks brings a “disturbing twist to the fight against insurgency.”

The nature of the organizations that employ female suicide bombers has changed.

Female suicide bombers were active in the 1980s in Lebanon and in the 1990s in Sri Lanka, Turkey and Chechnya. And by the turn of the century, female suicide bombers had spread to conflicts around the globe. What changed was the nature of the organization that employed them. Initially, leftist groups or secular organizations were more likely to employ a female in suicide attacks. Time and time again, they proved to be deadlier and more effective than men.

Bruce Hoffman illustrated how effective female bombers were in The Atlantic in June 2003:

“A person wearing a bomb is far more dangerous and far more difficult to defend against than a timed device left to explode in a marketplace. This human weapons system can effect last-minute changes based on the ease of approach, the paucity or density of people, and the security measures in evidence…In April of last year a female suicide bomber tried to enter the Mahane Yehuda open-air market—the fourth woman to make such an attempt in four months—but was deterred by a strong police presence. So she simply walked up to a bus stop packed with shoppers hurrying home before the Sabbath and detonated her explosives, killing six and wounding seventy-three.”

Most Islamist groups (besides the Chechens) were slow to adopt the strategy of female bombers either because they assumed they had more than enough men for the job or because the social limitations of women traveling without a chaperon (Mahram) required additional considerations and planning for female bombers. Some feminist scholars (e.g., Andrea Dworkin) assumed this reticence might also be a function of wanting to limit women’s roles in political violence lest this influence women’s power in a patriarchal society and politics as a whole.

The Islamic groups had an infinite ability for adaptation and doctrinal flexibility. Starting in 2004 with the release of a Web-based magazine called al Khansa’a, the evolution of religious ideology on female suicide bombers changed from advising women what to do while their men were on Jihad to telling women they, too, could be Jihadis and even be suicide bombers.

Why have Islamic groups recently taken so enthusiastically to including female suicide bombers?

I highlight four primary changes.

First, there has been an ideological shift. Debates emerged on-line and fatwas were issued stating that women’s obligation for Jihad is equal to that of men. This was largely led by Sheikh Yusuf al Qaradawi, an Egyptian cleric living in Qatar who has legitimized the use of women as suicide bombers.

Second, Al Qaeda’s structure changed. As the central core of Al Qaeda gave way to a host of regional affiliates, those affiliates were more inclined to involve women in front-line violent activities. While al Qaeda’s leaders swore that there were no women in the organization, Al Qaeda in Iraq, al Shabaab, Chechen militant groups in Chechnya and Dagestan, and groups in Pakistan and Uzbekistan and others began using female bombers as early as 2005. It’s only recently that female bombers have emerged among the Taliban in Pakistan and Afghanistan, relatively late adopters compared to the affiliated groups killing Western contractors or people in line for food aid.

Third, there were changes in targeting. Women are ideal operatives when attacking soft targets and blending in with civilians. As terrorist organizations have shifted from attacking military targets (hard targets) to civilian targets (soft targets), women have been especially useful. When an improvised explosive device is strapped around a woman’s midsection, it gives the impression that she is pregnant, throwing off security forces who don’t expect a woman — let alone one who is pregnant — to be carrying a bomb. As a result of the existing stereotypes we have of the inherent peacefulness of women, they are less likely to be searched at checkpoints and if the security services are too invasive (and reports of sexual violations at checkpoints is common in many of these conflicts), then invasive searching of women in traditional settings only helps the terrorist organizations recruit more men who are outraged that women are being abused.  Mobilizing men to protect the honor of women is hardly a new tactic and was extremely effective in the 1960s and 1970s for the provisional IRA who used the strip-searching of Republican women in Belfast by the RUC to motivate men to join the movement.

Finally, including women offered a new mobilization strategy – not just of women, but also of men. Women serve a unique purpose in helping mobilize men into terrorist organizations. It is a powerful narrative when women (especially online) accuse men of being unmanly unless they step up and join the Jihad to protect their sisters in Islam. In addition to tapping 50 percent of the population, recruiting women is an effective strategy of goading men into participation. This also explains the effectiveness of women online as propagandists, fundraisers and recruiters for terrorist groups.

When are female suicide bombers used most often?

That said, my research suggests that terrorist groups tend to gravitate toward female operatives not when they are at their strongest but when they are at their weakest. Terrorist groups include women either because they are having a difficult time accessing hard targets — which are more valuable in the long term for their struggle — or because men are not signing up unless they are guilted into it. The fact that Boko Haram is using women may be an indication of their weakness more than their strength.