The attack is over, the BBC reports, and all the students are accounted for.

The number of people killed in an attack by al-Shabab Islamist militants on a university in north-eastern Kenya has risen to 147, Kenyan government officials say.

The operation to secure the Garissa University College campus was now over, with all four attackers killed, they added.

Officials said 587 students had been evacuated, 79 of whom were injured.

Nine who are critically injured have been airlifted to Nairobi for treatment.

Student Collins Wetangula said when the gunmen entered his hostel he could hear them opening doors and asking if the people inside were Muslims or Christians, the AP news agency reports.

“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.

Al-Shabab says it attacked the university because it is at war with Kenya, BBC Africa analyst Mary Harper reports.

Kenyan troops entered Somalia in October 2011 in an effort to stop the Islamists from crossing the long, porous border between the two countries and kidnapping people – but their presence achieved the opposite effect, provoking al-Shabab to increase its activity in Kenya, our correspondent adds.

Because how dare Kenya try to stop al-Shabab kidnapping people in Kenya? Keny must understand that al-Shabab can do whatever it wants to, because Allah.

147 killed. A morning’s work.