At least 147 people were killed after the Somali militant group Shabab attacked a university in eastern Kenya, the country's Interior Ministry said as it announced that the fighting had ended.
All four attackers had also been killed, the ministry said. It was not immediately clear whether they included a suspect earlier reported captured or if that report had been inaccurate.
Scores of people were wounded and 500 had been accounted for, according to the Kenya National Disaster Operation Center. The university normally has about 815 students in residence.
Amref Health Africa, a Kenyan health organization that was one of the first responders on the scene, said in a statement that 25 bodies had been removed from one classroom after the attack on Garissa University College.
Nine critically injured victims of the attack had been airlifted to Nairobi for treatment, according to the Kenya National Disaster Operation Center.
Shabab, an Al Qaeda-linked group, claimed responsibility for the attack.
Authorities named the terrorist commander behind the attack as ethnic Somali Mohammed Mohamud, who also goes by the names Dulyadin and Gamadheere. The Interior Ministry released a photograph of Mohamud and offered a $220,000 reward for information leading to his arrest. Authorities had placed a $55,000 bounty on his head in December.
Shabab said in a statement that the university was on Muslim land and was there to promulgate "missionary activities and to spread deviant ideology."
The attack comes less than a week after a Shabab attack on a hotel in the Somali capital, Mogadishu, which killed 24 people.
Thursday's attack began about 5:30 a.m. when gunmen stormed the campus as some Muslim students were rising for morning prayers.
Students fled in terror as the attackers sprayed the campus with gunfire. The sounds of heavy gunfire rang out as the day wore on, with reports that Shabab gunmen had taken positions on the roof, firing at security forces and anyone who tried to escape.
Interior Minister Joseph Nkiassey said an operations center had been established to coordinate the multi-agency response to the attack that included both the military and police. Tanks were deployed.
According to the Reuters news agency, a Shabab spokesman, Sheik Abdiasis Abu Musab, said the group spared Muslim students — a hallmark in previous Shabab attacks that had singled out Christians. The approach differentiates the group from Islamic State affiliates in Africa such as Nigerian terrorist group Boko Haram.
He claimed there were many dead and that the attackers at one point were holding many Christian students hostage.
Eyewitnesses described terrifying scenes as the gunmen attacked at dawn.
"All I could hear were footsteps and gunshots — nobody was screaming because they thought this would lead the gunmen to know where they are," student Collins Wetangula told the Associated Press. He said he and others locked themselves in their room, but gunmen came looking for Christian students.
"If you were a Christian, you were shot on the spot. With each blast of the gun I thought I was going to die," he said.
He said he and other students were saved when the Kenyan military arrived, driving the gunmen away and leading him and about 20 others to safety.
University staff said they tried to contact students inside the campus by phone but had been unable to do so, according to local media.
The attack comes days after warnings of a possible terrorist attack in Kenya. The British and Australian governments drew harsh criticism from the Kenyan government after Australia warned of possible terrorist attacks in Nairobi, and Britain warned its citizens to avoid travel to most coastal and northern areas.
Some critics said security at the university was inadequate, given previous attacks by Shabab in northern Kenya.
Police spokesman Joseph Boinnet said the officers on duty engaged the attackers in a fierce gun battle but that the gunmen managed to gain access to the campus.
"The attackers shot indiscriminately while inside the university compound," Boinnet said in a statement. "Police officers who were on duty at the time guarding the students' hostels heard the gunshots and responded swiftly and engaged the gunmen in a fierce shootout, however the attackers retreated and gained entry into the hostels."
Kenyan President Uhuru Kenyatta addressed the nation on television following the attack, announcing that he would send an extra 10,000 police recruits for 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, offering condolences to families of the dead. He offered no additional information about the number of victims except to say that several people were killed or wounded and that others were taken hostage.
"I also assure the nation that my government has undertaken appropriate deployment to the affected area," he said. "I also urge Kenyans to stay calm as we resolve this matter, and to provide the authorities with any information they may have in connection with any threats to our security.
Shabab, which is able to cross Kenya's notoriously porous border at will, has carried out several horrifying attacks since late last year, including the massacres of 28 bus passengers and 36 quarry workers.
Last year was the deadliest since 2011 — when Kenya began its military intervention in Somalia — with more than 90 people killed in terrorist attacks near Lamu on the coast by Shabab or related Kenyan groups.
Shabab has suffered recent setbacks in Somalia, with the killings of its secretive commander, Ahmed Abdi Godane, and other top figures in recent U.S. airstrikes. But it remains capable of carrying out devastating terrorist attacks, often using a handful of gunmen.
Its most notorious attack in Kenya was in 2013, when four gunmen killed 67 people at the upscale Westgate shopping mall in Nairobi.