An Islamist militant group called Al-Shabaab raided Garissa University College in Kenya Thursday and killed at least 147 people.

According to USA Today, Kenyan Interior Cabinet Secretary Joseph Nkaissery confirmed the terrorist attack had subsided and 147 were confirmed dead at the time.

However, the Independent reported, an unnamed source within the Kenyan police told the Press Association the death toll could climb as high as 160.

Sheikh Abdiasis Abu Musab, a spokesman for Al Shabaab, confirmed to Reuters the terrorist group "sorted people out" during the siege and "released the Muslims" while holding Christians hostage.

Police have been able to safely evacuate 500 of about 815 students at the school, Reuters reported. Nkaissery also said police killed four Al-Shabaab gunmen.

According to BBC News, Nkaissery said in his public remarks the violence was close to being over as of Thursday afternoon, as police were sweeping the campus for any remaining threats. Authorities have not confirmed the death toll as of yet.

In a summarization of the attack, BBC News reported five gunmen stormed the front gate and shot dead two security guards before opening fire on students and faculty in the library and classroom building.

Al-Shabaab was the Islamist militant group responsible for the 2013 mass shooting at the Westgate shopping mall in Nairobi. With loose ties to Al-Qaeda, Reuters noted, Al-Shabaab is known for carrying out similar attacks to retaliate against Nairobi for sending forces into Somalia.

When the shooting first broke out, some students were able to escape before law enforcement could get to the scene to help with the evacuation. Many of those did escape were able to do so through a fence behind the classroom building.

"We heard some gunshots and we were sleeping so it was around five and guys started jumping up and down running for their lives," one unnamed student told Reuters.

Dr. Sajjan Gohel, an expert on Islamist Ideology and doctrine at the London School of Economics, told CNN terrorist groups like Al-Shabaab target schools for a number of reasons, chiefly because they have the most news-making potential.

"Terrorists deem these institutions as soft, symbolic targets where they're able to get the oxygen of publicity," he said, "attract notoriety and spread the fear factor."