NAIROBI, Kenya -- Al-Shabab gunmen stormed a university in northeastern Kenya at dawn Thursday, killing at least 147 people in the group's bloodiest attack in the East African country, officials said. Four of the gunmen were killed by security forces.
In the attack, which turned into a hostage siege that continued into the evening at Garissa University College, masked militants separated Christian students from Muslims, and then gunned them down without mercy, survivors said. Others ran for their lives with bullets whistling through the air, and hundreds of students remained unaccounted for more than 11 hours after the bloodshed began.
At least 79 people were wounded at the school 145 kilometers (90 miles) from the Somali border by the al-Qaida linked group, said Interior Minister Joseph Nkaissery, who gave the death toll. A dusk-to-dawn curfew was ordered in Garissa and three nearby counties.
Kenyan security forces cornered the gunmen in a dormitory, and President Uhuru Kenyatta said in a speech to the nation that the attackers were holding hostages.
Ali Mohamud Rage, a spokesman for al-Shabab, said fighters from the Somalia-based extremist group were responsible. The al-Qaida-linked group has been blamed for a series of attacks, including the siege at the Westgate Mall in Nairobi in 2013 that killed 67 people, as well as other violence in northern Kenya.
Police identified a possible mastermind of the attack as Mohammed Mohamud, who is alleged to lead al-Shabab's cross-border raids into Kenya, and they posted a $220,000 bounty for him. Also known by the names Dulyadin and Gamadhere, he was a teacher at an Islamic religious school, or madrassa, and claimed responsibility for a bus attack in Makka, Kenya, in November that killed 28 people.
One of the survivors of Thursday's attack, Collins Wetangula, told The Associated Press he was preparing to take a shower when he heard gunshots coming from Tana dorm, which hosts both men and women, 150 meters (yards) away. The campus has six dorms and at least 887 students, he said.
When he heard the gunshots, he locked himself and three roommates in their room, said Wetangula, who is vice chairman of the university's student union.
"All I could hear were footsteps and gunshots. Nobody was screaming because they thought this would lead the gunmen to know where they are," he said.
He added: "The gunmen were saying, 'Sisi ni al-Shabab,'" - Swahili for "We are al-Shabab."
He heard the attackers arrive at his dormitory, open the doors and ask if the people who had hidden inside were Muslims or Christians.
"If you were a Christian, you were shot on the spot," he said. "With each blast of the gun, I thought I was going to die."
The gunmen then started shooting rapidly, as if exchanging fire, Wetangula said.
"The next thing, we saw people in military uniform through the window of the back of our rooms who identified themselves as the Kenyan military," he said. The soldiers took him and around 20 others to safety.
The attack began about 5:30 a.m., as morning prayers were underway at the university mosque, where worshippers were not attacked, said Augustine Alanga, a 21-year-old student.
At least five heavily armed, masked gunmen opened fire outside his dormitory, turning intense almost immediately and setting off panic, he told the AP by telephone.
The shooting kept some students indoors but scores of others fled through barbed-wire fencing around the campus, with the gunmen firing at them, he said.
"I am just now recovering from the pain as I injured myself while trying to escape, Alanga said. I was running barefoot," Alanga said.
As terrified students streamed out of buildings, arriving police officers took cover. Kenya's National Police Service said a "fierce shootout" occurred with police guarding the dormitories.
Authorities were only able to account for 292 of the university's 815 students more than 11 hours after the start of the attack that sent them scattering for safety, Nkaissery said. All 60 members of the school's staff were accounted for, he said.
Three of the dorms were evacuated, with the gunmen holed up in a fourth, the National Disaster Operations Center said on Twitter, and Kenya Defense Forces surrounded the campus.
"I am saddened to inform the nation that early today, terrorists attacked Garissa University College, killed and wounded several people, and have taken others hostage," Kenyatta said in his speech to the nation.
Michael Bwana, a 20-year-old student, said he and other survivors tried to call their friends trapped in a dormitory, but their phones were switched off - either by their owners to keep them from ringing or by the gunmen who have seized them.
"Most of the people still inside there are girls," Bwana said, referring to the dorm where gunmen are believed to be holding an unknown number of captives.
One suspected extremist was arrested as he tried to flee, Nkaissery told a news conference in Nairobi.
Wetangula, who was rescued by soldiers, said one soldier instructed his group of students to run and to dive for cover at the soldiers' command as they ran to safety.
"We started running and bullets were whizzing past our heads, and the soldiers told us to dive," Wetangula said. The soldier told students later that al-Shabab snipers were perched on a three-story dormitory called the Elgon, he said.
Some of the more seriously wounded were flown to Nairobi for treatment, authorities said.
Kenyatta has been under pressure to deal with insecurity caused by a string of attacks by al-Shabab.
In his speech to the country, he said he had directed the police chief to fast-track the training of 10,000 police recruits because Kenya has "suffered unnecessarily due to shortage of security personnel."
Kenya's northern and eastern regions near the Somali border have seen many attacks blamed on al-Shabab. The group has vowed to retaliate against Kenya for dispatching troops to Somalia in 2011 to fight the militants following cross-border attacks.
Last month, al-Shabab claimed responsibility for attacks in Mandera county on the Somali border in which 12 people died. Four of them died in an attack on the convoy of the county's governor.
Police said 312 people have been killed in al-Shabab attacks in Kenya from 2012 to 2014.
Last week, al-Shabab claimed responsibility for a siege at a Mogadishu hotel that left 24 people dead, including six attackers.