Video has emerged of the massacre at a university campus in northeastern Kenya in which 148 people were killed by Islamist extremists.
It shows students running for their lives and hiding behind bushes as bullets whistle through the air.
Four masked al Shabaab gunmen rampaged through Garissa University College at dawn on Thursday in the group's deadliest attack in the country.
They were eventually killed by security forces 13 hours later after a lengthy gun battle.
The attackers, who were strapped with bombs and armed with AK-47s, singled out non-Muslim students and gunned them down without mercy, survivors said.
They took dozens of hostages in a dormitory as they battled troops and police before they were hit by gunfire and exploded, according to Interior Minister Joseph Nkaissery.
He said 142 of the victims were students, but three police officers and three soldiers were also killed.
At least 79 people were wounded on the campus, which lies 145km (90 miles) from the Somali border. Some were flown to the capital Nairobi for treatment.
One suspected extremist was arrested as he tried to flee, Mr Nkaissery told a news conference.
One survivor, Collins Wetangula, told The Associated Press he was about to take a shower when he heard gunshots coming from a nearby dormitory, one of six on the campus.
"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 Shabaab."
He said he heard the attackers arrive at his dormitory, open the doors and ask if those 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."
He said fortunately soldiers then arrived and took him and around 20 others to safety.
Another student, Augustine Alanga, said the attack began at about 5.30am as morning prayers were under way at the university mosque, where worshippers were left alone.
At least five heavily armed gunmen opened fire outside his dormitory, sparking panic, he told AP. He said some students remained indoors but scores of others fled with the attackers firing at them.
Police say the massacre may have been masterminded by Mohammed Mohamud and are offering a large reward for information leading to his capture.
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.
A spokesman for Somalia-based al Shabaab said the college attackers were members of their al Qaeda-linked group.
Al Shabaab has been blamed for a series of attacks in Kenya, including the siege at the Westgate Mall in Nairobi in 2013 that killed 67 people, as well as other violence in the north.
The group has vowed to retaliate against the government for sending troops to Somalia in 2011 to tackle militants staging cross-border raids.
