Gunmen hijacked a bus in northern Kenya before executing 28 non-Muslims on board after they had been singled out from the rest of the passengers, police officials said Saturday, blaming the attack on al Shabaab Islamic extremists from Somalia.

Gunmen hijacked a bus in northern Kenya before executing 28 non-Muslims on board after they had been singled out from the rest of the passengers, police officials said Saturday, in an attack claimed by al Shabaab Islamic extremists.

"I can confirm... that 28 innocent travellers were brutally executed by al Shabaab," said regional police chief Noah Mwavinda.

He said the gunmen forced the bus to stop and drove it to the side of the road, where they proceeded to kill passengers identified as non-Muslim.

The bus had been travelling to the capital Nairobi with 60 passengers when it was hijacked 50 kilometres (31 miles) from the town of Mandera near Kenya’s border with Somalia, police sources said.

Some of the dead were public servants who were heading to the capital Nairobi for the Christmas vacation, they said.

A spokesman for al Shabaab said the Somalia-based militant group claimed responsibility for the attack.

He said the killings were in revenge for raids that Kenyan security forces carried out over the past week on mosques in the port city of Mombasa.

One person was shot dead and more than 350 people arrested as security forces searched mosques for weapons and al Shabaab supporters.

Kenya has suffered a series of attacks since invading Somalia in 2011 to attack al Shabaab, later joining an African Union force battling the Islamists.

The group carried out the September 2013 attack on Nairobi's Westgate shopping mall, killing at least 67 people as a warning to Kenya to pull its troops out of southern Somalia.

During the Westgate attack, the gunmen weeded out non-Muslims for execution by demanding they recite the Shahada, the Muslim profession of faith.

(FRANCE 24)