'Suspected members of the Somali militant group al-Shabab have killed at least 28 people in an attack on a bus in northern Kenya, officials say.The bus was travelling to the capital, Nairobi, when it was stopped in Mandera county, near the Somali border.After taking it off the road, gunmen separated out those they thought were non-Muslim before killing them, officials said.Somalia-based al-Shabab has been mounting attacks in Kenya since 2011.That was the year when Kenya sent troops to Somalia to help fight the Islamist militia. Mandera, a remote area in Kenya's north east, has been one of the regions affected.Kenya's interior ministry said on its Twitter feed that the bus attacked early on Saturday had been carrying 60 passengers.One official told Kenya's Daily Nation newspaper that assailants had asked passengers to read out verses of the Koran, before executing those who failed.'Can you see the less than subtle attempt to hide who these terrorists are? No mention of the facts that they are is Islamist terrorists killing non Muslims only in the lead in paragraph, because that's all that most people read if they read the article at all. And because that's what forms the headline line on the main news pages. For the BBC who are desperately trying to pretend that Islamic terrorists are not involved in a war against non Muslims that is very very important. Facts be dammed, there's a propaganda war to win.'