The University of Nairobi, Kenyatta University and the United States International University - Kenya had all issued security memos days before the attack on Garissa University claimed by Somali Islamist militant group al-Shabaab.

The memos informed students and staff of new security measures while cautioning people within their campuses to be extra vigilant.

University attack security memo
Memo pinned on the Kenyatta University notice board warning about potential attackTwitter

In a note dated 25 March, the University of Nairobi warned "intelligence reports indicate that the al-Shabaab terror group is planning retaliatory attacks on (...) a major university".

The universities had informed students and staff of new security measures while cautioning people within their campuses to be extra vigilant.

According to the university in the capital, "the information [was] already being processed by the relevant government agencies with an objective of putting necessary measures in place to fail any such attempts".

Garissa Kenya al-Shabaab
University students leave after escaping an attack by al-Shabaab gumen in GarissaAFP

Students asked to co-operate with security personnel

Professor Paul Wainaina, deputy vice chancellor of administration at Kenyatta University, sent out a memo on 1 April requesting students cooperate with the security personnel.

"In view of the potential risks, our security system has become extra vigilant and as a result screening of all persons entering Kenyatta University premises has been intensified, among other measures," the memo said.

Attack Memo
Memo sent by Kenyatta University warning about potential attackTwitter

Grace Kai, a student at Garissa Teachers Training College next to the campus that was attacked, told Reuters there had been warnings an attack could be imminent.

"Some strangers had been spotted in Garissa town and were suspected to be terrorists," she said.

"Then on Monday our college principal told us... that strangers had been spotted in our college... On Tuesday we were released to go home, and our college closed, but the campus remained in session, and now they have been attacked."

April fools

Unfortunately, students who were warned of potential attacks thought the warnings were April Fools pranks.

A student survivor of the Garissa attack told Akasha Opato Daawah, a trading company director based in Mombasa, that warning notices were put up, "but as it was April 1, we thought that it was fooling".

Al-Shabaab was responsible for a deadly attack in 2013 on the upscale Westgate shopping mall in Nairobi. The group has vowed to punish Kenya for sending troops into Somalia alongside African Union peacekeepers to fight the group.

312 people have been killed in al-Shabab attacks in Kenya from 2012 to 2014, according to police statistics.

Thirty-eight people were killed and 149 wounded in Garissa in the same period.

Keep updated on the Garissa attack.