Maltese Bishop Joseph Alessandro has thanked and praised the faithful for going to Church in Garissa, Kenya, despite the attack by Islamist militants last week which left 148 Christians dead.

The attack took place in the University of Garissa, up the road from where Mgr Alessandro lives.

"Thank you for coming, so many of you," Bishop Alessandro told the congregation as quoted by the Associated Press.

He said some of those who died in Thursday's attack would have been at the service, and he read condolence messages from around the world.

Mgr Alessandro said he saw a parallel between the ordeal of Jesus Christ, which Easter commemorates, and that of Garissa.

"We join the sufferings of the relatives and the victims with the sufferings of Jesus," he said. "The victims will rise again with Christ."

Mgr Alessandro has been serving in Garissa since 1989 and was himself shot and injured by bandits on a trip outside the town several years later.

He said there had been development in recent years in the area, as well as an increase in insecurity because of al-Shabab.

"You don't know who they are. They could be your neighbors," he said. A heavy security presence only helps up to a point and more intelligence on the militants is needed, he told AP.

Amid their grieve the Christians prayed, sang and clapped hands at an Easter Sunday service in Our Lady of Consolation Church as soldiers patrolled outside.

The church was attacked by militants almost three years ago when grenades lobbed at the building sprayed shrapnel into the interior, injuring some worshippers. Another Garissa church was also attacked that day. Seventeen people died.

Today's ceremony was laden with emotion for the several hundred members of Garissa's Christian minority, which is fearful following the attack by al-Shabab, Ap said.

The gunmen who attacked Garissa University College on Thursday singled out Christians for killing, though al-Shabab has a long record of killing Muslims over the years.

"We just keep on praying that God can help us, to comfort us in this difficult time," said Dominick Odhiambo, a worshipper who said he planned to abandon his job as a plumber in Garissa and leave for his hometown because he was afraid. 

The church service was spirited, combining incense, candles and other traditions with local, upbeat singing styles. Worshippers swayed to the rhythm of the hymns in the simple structure, with latticed walls that let light and a breeze through rectangular openings. Fans mounted above images of the stations of the cross helped to cool the crowd. Birds chirped from the upper reaches of the high ceiling, which consists of metal sheeting.

Roseline Oduor said she is worried because the church had been attacked in the past.

"Having courage as a Christian, we just have that faith with coming to church," Oduor said. "We have gone through what Jesus went through."

She said: "When the day comes, you cannot run away from death, whether under a tree, in bed, anywhere."