Three Christian teachers have been killed in an attack on a Kenyan primary school by militants believed to belong to the Somalian terrorist group al-Shabaab. 

The school was attacked by gunmen in the early hours of Monday in the town of Kamuthe in Garissa County, in eastern Kenya.

A police post and telecommunications mast was also attacked. 

The victims were named by International Christian Concern as Caleb Mutua, Titus Ushindi, and Samuel Muthui Kyonzu. A fourth victim, Joshua Mutua, sustained serious leg injuries but survived the attack. 

The Associated Press, citing a police report, said that the assailants spared the life of a female nurse and abducted one Muslim teacher. 

Robert Kibutu, a local teacher, told ICC that he fears more attacks.  He said that Christian teachers were being targeted because of their faith.

"We are sad and at the same time scared because we are targeted for being non-local government workers that belong to the Christian faith," he said. 

Al-Shabaab has repeatedly targeted Christians.  In December, suspected al-Shabaab extremists killed at least eight Christians during an attack on a bus travelling from Nairobi to Mandera. 

In 2015, al-Shabaab gunmen stormed the campus of Garissa University, killing 148 people, mostly Christians.