Al-Shabaab militants claim to be behind Kenyan siege
Somali militant group al-Shabaab has claimed responsibility for the deadly attack on a Nairobi shopping centre where at least 68 are thought to have been killed during an ongoing siege.
The extremist group was formed in 2006, emerging from the Islamic Courts Union that ran the Somali capital, Mogadishu, for six months before being driven from power.
Its name means "The Youth" in Arabic and it was created in a bid to establish a fundamentalist Islamic state in the East African nation
It has formally aligned itself with al-Qaeda, attracting hundreds of foreign fighters, including Britons.
There are reports that British female terror suspect Samantha Lewthwaite, nicknamed the White Widow, could have been linked to the plot. She was married to July 7 bomber Jermaine Lindsay and in March 2012 it was reported that the 29-year-old had fled across the border from Kenya to Somalia.
Ahmed Abdi Godane is the head of the group, which is believed to have several thousand fighters, and he is known as Mukhtar Abu Zubair.
The group was dealt a blow in February 2012 after troops from the African Union force in the country (Amisom) succeeded in driving the Islamist group from Mogadishu.
Hopes for an end to their reign of terror were further bolstered by reports that the al-Shabaab stronghold of Baidoa in the south west of the country had fallen to troops from neighbouring Ethiopia and Somali government forces.
The group still exercises significant control over vast swathes of the south towards its border with Kenya.
Al-Shabaab has claimed responsibility for several deadly suicide bombings, including one in February 2009, which killed 11 Burundian soldiers on an African Union peacekeeping mission.
It carried out its first major international attack in July 2010 when it bombed the Ugandan capital, Kampala, killing at least 74 people.
In late 2011 al-Shabaab vowed to carry out a large-scale attack in Nairobi in retaliation for Kenya's sending of troops into Somalia to fight the Islamic insurgents.
The group, also known as Harakat al-Shabaab al-Mujahideen (HSM), has been vocal on the social media site Twitter in recent years. It appeared to claim responsibility for the atrocity by writing on its official feed on Saturday but the account has since been suspended.