NEW DELHI: Al Shabaab -- a militant group active in Somalia and Kenya -- ambushed a bus headed for Kenya’s capital, Nairobi, killing 28 non-Muslim passengers in what the group said was revenge for police raids on mosques in Mombasa.

"I can confirm... that 28 innocent travellers were brutally executed by the Shabaab," regional police chief Noah Mwavinda told AFP. The militants divided the passengers on the bus into Muslims and non-Muslims, loading the non-Muslim passengers back onto the bus, driving off with them and executing them.

Al Shabaab’s spokesperson claimed responsibility for the attack. "The Mujahedeen successfully carried out an operation near Mandera early this morning, which resulted in the perishing of 28 crusaders, as a revenge for the crimes committed by the Kenyan crusaders against our Muslim brethren in Mombasa," Ali Mohamud Rage said in a statement sent to AFP.

Al Shabaab militants have been in the international spotlight for their attacks in Kenya and Somalia, most recently explosions in Nairobi earlier this year and the infamous West Gate Mall attack that killed 67 people. The group took responsibility for the attack as retribution for the Kenyan government’s decision to send troops into Somalia to fight alongside government forces.

Al-Shabaab declared jihad on Kenya as far back as 2010 on allegations that the Kenyan government was training Somali troops, which Kenya denied. This threat was heightened post 2011 when the Kenyan government sent troops as part of a United Nations backed African Union force that pushed al-Shabaab militants out of Somalia's capital, Mogadishu in 2011, and out of the vital port of Kismayo in 2012. The port has been a vital asset for the militants, enabling supplies to reach areas under the group’s control and providing taxes for its operations.

After 2011, al-Shabaab’s influence in Somalia was reduced from control over large swathes of the country’s central and southern areas, including its capital, to limited rural areas. Kenyan troops continue to serve as part of the African Union force, playing a pivotal role in capturing areas from al-Shabaab’s control.

The al-Shabaab group carries out attacks within Somalia often. In March this year, the militants led a suicide raid on a hotel in the southern town of Buuloburde, killing a number of people days after the town was recaptured from the militants. The attack followed an assault on a military convoy near the capital city, killing four Somali soldiers. In February, 14 people were killed as the group attacked the Somali presidential palace although Somali president, Hassan Sheikh Mohamud, was unharmed.

Al-Shabaab’s control of parts of Somalia’s countryside and smaller towns is being used by the militants as a launchpad to plan and execute attacks in the country and beyond Somalia’s borders, examples being the attacks in Kenya. In addition to Kenya, the group has specifically targeted Uganda, also a neighbouring country that has contributed fighters to the African Union force. The deadliest attack in Uganda by the militant group killed 64 people in Kampala as they watched the World Cup final in 2010.

The group, which has links to Al-Qaeda, has denounced the 2012 election of President Hassan Sheikh Mohamud, which was backed by a UN-brokered peace process, as a foreign plot to control Somalia. The group’s rise to influence can be located within the political context of Somalia, which has lacked an effective national government for over twenty years, making the group’s promise of security appealing to the country’s population. The Somali government maintains that the group’s presence is on the decline and the militants are on the verge of being defeated. A Twitter account run by the President’s office posted, “Don't be fooled by this media spectacular [sic]. This is another act of desperation from a dying animal,” following the attack on the palace.

Is al-Shabaab a “dying animal”? This latest incident proves otherwise.