It took just four gunmen to demonstrate Kenya's impotence against the Somali militant group Shabab.
In an attack heavy with foreboding symbolism, Shabab massacred 147 college students, all or most of them Christians, in the eastern city of Garissa on the eve of Good Friday. At least 79 were injured, and the four gunmen were also killed.
Survivors described their terror Thursday as gunmen searched dormitories, asking students whether they were Muslims and executing any Christians.
Earlier in the day, Kenyan President Uhuru Kenyatta downplayed the attack's severity, although it was known that hundreds were trapped, telling Kenyans that several were killed and wounded.
Unconfirmed local news reports suggested some students at Garissa University College were beheaded, as furious critics railed at the failure of security forces to prevent mass terrorist attacks on civilians.
Many said authorities should have boosted security at the campus, an obvious target with a mixed Muslim and Christian student body in northern Kenya, after specific intelligence warnings in recent days of an impending attack on a Kenyan university. Others bemoaned that a tragedy mirroring Shabab's 2013 attack at the Westgate mall in Nairobi, the capital, which killed 67, could have occurred, with even greater casualties.
Survivors described how men with machine guns swiftly shot down the two police officers guarding the college before swooping into the campus, spraying bullets everywhere and taking control of one dormitory.
The targeting of Christians, a classic Shabab tactic, is designed to ramp up tension between the nation's Muslim and Christian populations, helping it attract more recruits, analysts said.
The attack also underscored the persistent failures of Kenya's security services: the corruption that allows Shahab fighters to easily penetrate the border and move around the country; the intelligence shortcomings; and the heavy-handed harassment of Kenya's Muslim population that drives alienated, jobless young men into the arms of extremists.
More than 100 students were held hostage on the campus as the 15-hour siege dragged into the night. As darkness fell, a series of deafening explosions rang out, according to reports from the scene.
"The operation has ended successfully. Four terrorists have been killed," Interior Minister Joseph Nkaissery told reporters in Garissa. In the grisly finale, the gunmen, strapped with explosives, were blown up as Kenyan forces moved in, firing, he said.
Shabab has suffered recent setbacks in Somalia, with the killings of its secretive commander, Ahmed Abdi Godane, and other top figures in U.S. drone attacks. But it remains capable of carrying out devastating attacks in Somalia and neighboring countries, often using just a few gunmen.
The attack Thursday was its bloodiest, and the second deadliest in Kenya after the 1998 U.S. Embassy bombing in Nairobi.
Ken Menkhaus, a Shahab and terrorism expert at Davidson College in North Carolina, said that though the group was growing weaker in Somalia, it was gaining strength in Kenya. He described the college attack as "tragic and predictable."
"They have been looking at soft targets in northern Kenya where they can operate more easily than in Nairobi," he said. "It was a very easy target of opportunity for them that was going to have a very big impact on Kenyans."
Officials said all students were accounted for. More than 800 were on campus during the attack; 587 fled or were rescued, a figure that apparently does not include the injured. Dozens of injured students were flown to Nairobi for treatment.
Authorities named the commander behind the attack as a former schoolteacher, Mohammed Mohamud, an ethnic Somali who also goes by the names Dulyadin and Gamadheere and is a major Shabab figure from southern Somalia's Middle Juba region. The Kenyan Interior Ministry released a photograph of Mohamud and offered a reward of $220,000 for information leading to his arrest. Authorities placed a $55,000 bounty on his head in December.
Claiming responsibility for the attack, Shabab said in a statement that the university was on Muslim land and was there to promulgate "missionary activities and to spread deviant ideology."
Garissa is a nonsectarian, public institution that specializes in science and technology.
The attack came less than a week after a similar Shabab attack on a hotel in the Somali capital, Mogadishu, killed 24 people. In an unusual departure from its focus on East Africa, Shabab also recently threatened an attack on an unspecified American mall.
Kenya's government, desperate for a solution, any solution, to the country's security crisis, plans to build a wall on part of its 450-mile northern border with Somalia, said Issa Timamy, governor of Lamu state, the site of several deadly attacks in 2014. But critics said a wall wouldn't work, especially without an improvement in the training and quality of security personnel.
Human rights groups have reported extrajudicial killings of suspects by security forces, including several clerics on Kenya's coast, and the arrests of hundreds of Somalis at a time.
One leading Shabab expert, Stig Jarle Hansen, said that Kenyan police were so corrupt that it was easy for detained Shabab members to bribe officers to let them go, and that the border was so porous and poorly protected that Shabab could easily strike in Kenya.
Shabab carried out numerous attacks near the border last year, including the massacres of 28 bus passengers and 36 quarry workers near Mandera, and the killings of more than 90 people in several attacks near Lamu on the coast.
"The border is totally leaky, partly because it's huge, but partly because of the level of corruption amongst the Kenyan border services," said Hansen, who has written a book about Shabab.
He said that at times the statements of Kenyan politicians were obviously false. A recent Shabab video lampooned the president, Kenyatta, who insisted that last year's attacks on Mpeketoni, near Lamu, were by local political forces. The video showed Shabab forces in Mpeketoni, with Kenyatta behind them on television denying they were there.
"It was gift wrapping for Shabab. At times Shabab has been more correct in its information than the Kenyan government," Hansen said.
He said the mass arrests and allegations of extrajudicial killings damage "the reputation of the Kenyan security services in the eyes of the people, who can become potential recruits. All these problems give Al Shabab a big operational advantage and a big propaganda advantage."
Menkhaus said Shabab, allied with Al Qaeda, had been overshadowed in recent months by Islamic State, which has attracted thousands of foreign recruits.
"Some of what they're doing is to try to regain ground. They've been completely overshadowed in the public eye by the Islamic State in the past year. These attacks are some attempt to try to regain attention, and they've succeeded in doing that," he said.
Menkhaus said that apart from creating border security services and police who were more committed and less corrupt, authorities needed to win back the Muslim population, many of whom were indifferent to or passively supportive of Shabab because they felt alienated by the abuses of security forces.
Kenya is more than 80% Christian. About 11% of the population is Muslim.
"Winning back commitment from all of the Kenyans, so that when they see something suspicious they report it, and there's police follow-through, these are things that need to be addressed immediately," he said.
Shabab's attacks, he said, aimed to "drive a wedge between the Muslim population and the Kenyan state and rest of society. It's incumbent on the Kenyan government not to allow them to frame it that way, and to respond in a way that doesn't allow them to do that."
One longtime anti-corruption campaigner, John Githongo, reacted angrily to the attack. "Garissa attack yet another outrage. Corruption and hubris costs us dear in the face of determined barbaric foes," he wrote on Twitter.
Kenyatta addressed the nation on television after the attack, announcing that he would speed up police recruiting by sending 10,000 new officers for immediate training to increase security.
"We have suffered unnecessarily due to a shortage of security personnel. Kenya badly needs additional officers, and I will not keep the nation waiting," the president said.