Christians in North Eastern Kenya have come under repeated attacks by Al-Shabaab militants but they continue to worship on Sundays under the protection of armed guards despite being warned not to do so by extremists.

Hundreds of students at Garissa University in northern Kenya came under attack in April when Al-Shabaab extremists crossed the border from Somalia and raided dormitories at the college.

They separated Christian students from their Muslim classmates and then killed 147 and wounded dozens more leaving the university empty to this day.

At Sunday Mass in Garissa's Cathedral, Our Lady of Consolation, the benches are full, CNN reports showing the congregation praying under armed guard but they're praying nonetheless.

Every Sunday new threats come from Al-Shabaab a terrorist group that claims to act in the name of Islam.

Garissa's Christians are told that if you worship here, you'll die, CNN reports.

Attending Sunday Mass, Patrick Gitau said that despite the risks: "Every Sunday I'm here it's my cathedral. Yeah I'm here I was baptized in this church."

Maltese priest Joseph Alessandro, now the Bishop of Garissa, who came to Kenya in the early 1990s, leads the congregation, himself a victim of attacks.

In 1993 he was shot by separatists on the Kenyan coast in 1993, and left the East African country to receive medical attention, but this did not deter his faith and he came back, to Garissa five years ago.

Despite constant threats before each Sunday mass, he told CNN he would never consider leaving his congregation.

"It's not a matter of choice," he says. "It's our duty to remain here. Since we are appointed as bishops, we have to stay - not withstanding what happens - 'til there are no Catholics, it's our duty to stay."

Following the campus attack, he says, many students have stopped attending their classes.

"Before the Garissa attack, we had 460 students in our school. After the attack, only 300 reported back. The others left Garissa or were scared to come back [to school] because of the attack."

Alessandro hopes that the institutions forced to shut down because of the threat of terror will soon reopen and that life will return to normal.

"Now we are gaining confidence again - we have security on the compound for the school and even during the night for the sisters, for the priests."

Along with his fellow bishops and nuns, they have stayed with the community.

Sister Evelyn Ingoshe, has been part of the Diocese of Garissa for two years. She works at the school next to the Garissa Cathedral.

Sister Evelyn told CNN that she loves children and it is for that reason that she has devoted her whole life to serve them.