Somali terrorists of the Al-Qaeda linked Al-Shabaab organization murdered 28 people in an attack on a bus in Kenya’s northeastern Mandera county on Saturday – before shooting their victims in the head they separated out the Muslims.

Around ten heavily-armed terrorists stopped the bus bound for Nairobi not far from the Somali border, forced passengers off, and then had them read from the Koran to pick out the non-Muslims and brutally shoot them, witnesses told BBC.

Ahmed Mahat, a passenger on the ill-fated bus, told the British news source there were over 60 passengers on board, and the driver tried to outpace the terrorists before getting stuck in mud.

“When we got down, passengers were separated according to Somali and non-Somalis,” Mahat said. “The non-Somalis were ordered to read some verses of the holy Koran, and those who failed to read were ordered to lie down. One by one they were shot in the head at point blank range.”

Mahat, a teacher from Mandera, said some Somalis who asked the terrorists not to shoot the non-Somali passengers were themselves shot.

Al-Shabaab released a statement saying the attack was “retaliation” for police raids on mosques in Mombasa earlier this week, in which security forces tried to crack down on weapons caches.

Mandera county where the attack occurred has a long border with Somalia, with guns passing freely over the border, and from southern Ethiopia where the Oromo Liberation Front operates.

Just over the border in Somalia, Al-Shabaab has a base called Gadondhawe which has been targeted by Kenyan airstrikes.