Accordidng to al Shabaab, the Qur'an sanctions sex with captive and slave women: "And all married women (are forbidden unto you) save those (captives) whom your right hands possess. It is a decree of Allah for you" (4:24). They see this is Sharia law.

MOGADISHU, Somalia — The girl’s voice dropped to a hush as she remembered the bright, sunny afternoon when she stepped out of her hut and saw her best friend buried in the sand, up to her neck.
Her friend had made the mistake of refusing to marry a Shabab commander. Now she was about to get her head bashed in, rock by rock.

“You’re next,” the Shabab warned the girl, a frail 17-year-old who was living with her brother in a squalid refugee camp.

By JEFFREY GETTLEMAN

Published: December 27, 2011 in the NY Times

Several months later, the men came back. Five militants burst into her hut, pinned her down and gang-raped her, she said. They claimed to be on a jihad, or holy war, and any resistance was considered a crime against Islam, punishable by death.

“I’ve had some very bad dreams about these men,” she said, having recently escaped the area they control. “I don’t know what religion they are.”

Somalia has been steadily worn down by decades of conflict and chaos, its cities in ruins and its people starving. Just this year, tens of thousands have died from famine, with countless others cut down in relentless combat. Now Somalis face yet another widespread terror: an alarming increase in rapes and sexual abuse of women and girls.

The Shabab militant group, which presents itself as a morally righteous rebel force and the defender of pure Islam, is seizing women and girls as spoils of war, gang-raping and abusing them as part of its reign of terror in southern Somalia, according to victims, aid workers and United Nations officials. Short of cash and losing ground, the militants are also forcing families to hand over girls for arranged marriages that often last no more than a few weeks and are essentially sexual slavery, a cheap way to bolster their ranks’ flagging morale. [...]
Somalia is a deeply traditional place, where 98 percent of girls are subject to genital cutting, according to United Nations figures. Most girls are illiterate and relegated to their homes. When they venture out, it is usually to work, trudging through the rubble-strewn alleyways wrapped head to toe in thick black cloth, often lugging something on their back, the equatorial sun burning down on them. [...]

At the same time, aid workers and United Nations officials say the Shabab, who are fighting Somalia’s transitional government and imposing a harsh version of Islam in the areas they control, can no longer pay their several thousand fighters the way they used to. Much as they seize crops and livestock, giving their militants what they call “temporary wives” is how the Shabab keep many young men fighting for them.

But these are hardly marriages, said Sheik Mohamed Farah Ali, a former Shabab commander who defected to the government army.

“There’s no cleric, no ceremony, nothing,” he said, adding that Shabab fighters had even paired up with thin little girls as young as 12, who are left torn and incontinent afterward. If a girl refuses, he said, “she’s killed by stones or bullets.” [...]
“You have no idea how difficult it is for them to come forward,” she said. “There’s no justice here, no protection. People say, ‘You’re junk’ if you’ve been raped.”...

The Rest @ NY Times