A Kenyan court on Wednesday found three men guilty of aiding gunmen in killing 148 people, mostly students, during the 2015 attack on Garissa University College.

Nairobi Chief Magistrate Francis Andanyi found Mohamed Abdi Abikar, Hassan Edin Hassan and Rashid Mberesero guilty of all 156 counts against them, including conspiracy to commit a terror activity, committing a terror activity and membership of a terror organization, KTN News Kenya reported.

A fourth suspect, Sahar Diriye, was acquitted as no link between him and the attack could be established.

"I have found that the accused were in active communication with the attackers," Andanyi said.

They are to be sentenced July 3 following further testimonies from four witnesses, including a police officer from a village where 11 people were killed that day.

The charges stem from a coordinated attack by five masked gunmen on the Kenyan university that left almost 150 people killed and over 80 injured.

Somali militant terrorist group Al-Shabab claimed responsibility. Four gunmen were killed during the attack. The attack's mastermind, Mohamed Kuno, was killed along with 16 others during a counter-terrorism operation the next year.

Al-Shabab has reportedly conducted several attacks in Kenya resulting in high numbers of fatalities since 2011 when Kenyan troops were deployed to Somalia as part of an African Union anti-terrorism force.