At least ten people were killed and several others injured after Islamist extremist group, Al-Shabaab, ambushed a commuter bus in northeast Kenya on Friday evening, the police said.

Stephen Ngetich, Wajir county police commander, said the militants ambushed a Medina Bus which was traveling from Nairobi to Mandera in the northeast region and killed Christians onboard.

Ngetich said the incident took place in an area between Wargadadud and Kutulu town in Wajir County at around 5 p.m.

“I can confirm there was an attack on the bus which was en route to Mandera from Nairobi. Most of the people targeted are non-locals. We are pursuing the attackers,” Ngetich said.

He said the bus is currently at the police station as an investigation into the incident is underway.

Witnesses said three non-locals or Christians managed to escape, one unhurt.

Preliminary reports indicate that the majority of the victims are police officers who were going back to their duty stations in Elwak and Mandera near the border with Somalia.

The unconfirmed report reveals the militants suspected to have crossed from neighboring Somalia separated the passengers into two groups before shooting the non-locals.

Kenya’s northeastern region has borne the brunt of grenade and gun attacks in the last several years since Kenya took its troops to Somalia in 2011 to fight the Al-Shabaab.

Many people, majority of whom non-locals or Christians, have as a result lost their lives with others left with permanent injuries.

Al-Shabaab has since changed tactics and resorted to abductions and using improvised explosive devices to carry out attacks in parts of the Coast and northeastern regions, according to police.