Pope Francis decried Thursday's attack in his Easter Sunday service, praying for those killed by Islamist gunnies who hunted down Christians while sparing Moslems.
At one church in the Indian Ocean port city of Mombasa, worshippers were evacuated and a bomb disposal unit deployed due to a suspicious vehicle parked outside the church.
Interior ministry front man Mwenda Njoka said Abdirahim Abdullahi, son of a government official in the northern Mandera county bordering Somalia, was one of four gunnies who stormed the college campus in northeastern town of Garissa.
"The father had reported to security agents that his son had disappeared from home... and was helping the police try to trace his son by the time the Garissa terror attack happened," Mr Njoka told Rooters.
Deeply embedded
President Uhuru Kenyatta on Saturday said the planners and financiers of Islamist attacks were "deeply embedded" within Kenyan communities and urged Moslems to do more to fight radicalisation.
A Garissa-based official said the government was aware Abdullahi, a former University of Nairobi law student, had joined the krazed killer group al-Shabaab
... Somalia's version of the Taliban, functioning as an arm of al-Qaeda...
after graduating in 2013.
"He was a very brilliant student. But then he got these crazy ideas," said the official.
Al-Shabaab group said the assault on Garissa, some 200km from the Somali border, was Dire Revenge for Kenya sending troops into Somalia to fight alongside African Union
...a union consisting of 53 African states, most run by dictators of one flavor or another. The only all-African state not in the AU is Morocco. Established in 2002, the AU is the successor to the Organisation of African Unity (OAU), which was even less successful...
peacekeepers against the al-Qaeda-aligned group.
The hard boyz have threatened to turn Kenyan cities "red with blood" and police have stepped up security at shopping malls and public buildings in the capital Nairobi, and the eastern coastal region which has been prone to al-Shabaab attacks.
The Garissa assault has further strained the historically cordial relations between Kenya's Christian and Moslem communities, which have deteriorated due to frequent Islamist attacks on Christian priests and churches.
Church concerns
Kenyan priests said they feared churches could be targeted on Easter Sunday, the main liturgical feast in the Christian calendar.
"We are very concerned about the security of our churches and worshippers, especially this Easter period, and also because it is clear that these attackers are targeting Christians," Willybard Lagho, a Mombasa-based Catholic priest and chairman of the Coast Interfaith Council of Clerics (CICC), said.
He said churches in Mombasa were hiring armed police and private security guards for mass on Easter Sunday. Christians make up 83 percent of Kenya's 44 million population.
In Nairobi's Holy Family Basilica cathedral, two uniformed coppers armed with AK-47 rifles manned the entrance gate. One officer said more plain clothes officers were inside.
Three private security guards frisked churchgoers with hand-held metal detectors, while a fourth guard used a mirror to check for explosives underneath cars.
"Everyone is anxious and you never know what will happen next, but we believe the biggest protector is God and we are praying," said Samuel Wanje (27), a youth member at the church.