Africa 23 September 2013 What you need to know about al-Shabab How the militant Somalia group behind the deadly attack on a Kenyan shopping centre formed, and why it is attacking foreign targets now. Sign UpGet the New Statesman's Morning Call email. Sign-up It didn’t take long for the Somali militant group, al-Shabab, to claim responsibility for this weekend’s deadly attack on the Westgate shopping centre in Nairobi. The group, which has a strangely active social media presence despite repeated attempts to close down its twitter feeds, claimed responsibility via twitter and said they were retaliating against Kenyan troops currently fighting militant groups in southern Somalia. Al-Shabab, which means “the youth” in Arabic, was originally the militant, youth arm of the Islamist coalition the Islamic Courts Union. When Ethiopia invaded Somalia in 2006, al-Shabab gained prominence as part of the armed resistance movement. It flourished in the lawlessness that followed Ethiopia's withdrawal in 2009, bolstered by funding from Eritrea. In 2011 Somalia and African Union forces forced al-Shabab out of Somalia’s capital, Mogadishu, but large swathes of the country are still under al-Shabab control. Those under al-Shabab rule are subject to the most draconian interpretation of Sharia law, which is violently enforced. Football and music are banned, women are forced to cover their faces in public, and are lashed if they don’t obey. Al-Shabab officially joined Al Qaeda in February 2012, but has long aligned itself with Al Qaeda’s narrative of global jihad, and was first designated by the US as a terrorist organisation in 2008. In 2010 it carried out its first overseas terrorist attack, when two suicide bombers killed 67 people watching the World Cup Final in Kampala, Uganda. Since 2011 al-Shabab has carried out a number of smaller attacks on bars, tourist resorts, churches and military sites in Kenya. One puzzling aspect of al-Shabab’s latest attack is that many believed al-Shabab was weakening. In September 2012 it was forced out of the strategic port town of Kismayo. The same year, Somalia's first formal parliament in more than 20 years was sworn in, a sign of improved security and confidence. On 16 September this year, the Somali government secured ₤1.5bn funding from the EU to rebuild the country. Al-Shabab has also fallen victim to infighting. Its co-founder Ibrahim al-Afghani was killed earlier this year, and several high profile members fled or turned themselves in to government forces following a coup by Ahmed Abdi Godane. Godane is believed to be a keen advocate of closer association with Al Qaeda, and as early as July this year, analysts predicted that Godane’s leadership would lead to an escalation of violence. As Simon Tisdall concludes in today’s Guardian: "The terrorists are divided and losing ground. But they seem determined to go down fighting." › How Labour can turn the economic recovery to its advantage An image grab taken from AFP TV shows Kenyan troops taking position on 21 September, 2013 inside the Westgate mall in Nairobi. Photo: Getty Sophie McBain is a special correspondent at the New Statesman. She was previously an assistant editor. Subscribe For more great writing from our award-winning journalists subscribe for just £1 per month!