Kenyan security authorities were warned of the threat of a terrorist attack on the upscale Westgate Mall prior to the multi-day assault that began on Sept. 21, and left more than 60 dead and 170 injured.
A leaked Kenyan intelligence report seen by the Wall Street Journal compiled briefings from the previous year that points to the threat of attacks on the Westgate Mall and a regional church by Somali militant group al-Shabab. It did not provide evidence to support the claim, but did include the names of three potential attackers: Sheikh Abdiwelli Mohamed, Sheikh Hussein and Sheikh Hassan.
Al-Shabab has not yet identified any of its members who were involved in the attack, which began on Saturday, Sept. 21. It ended the following Tuesday as Kenyan forces laid siege to the mall, ultimately ending with part of the building collapsing and trapping some inside.
The intelligence report also included a threat against Israeli citizens and assets in the region. Israel is a partial owner of the Westgate Mall, and sent security forces to the scene of the attack as it was unfolding. AFP reported Israeli special forces participated in the operation.
Kenyan authorities declined to discuss the leaked report with the Journal.
"Leaked intel is unverified, so we have no comment," said presidential spokesman Manoah Esipisu. "In general, we receive all kinds of intel all the time which we do not discuss with the media."
The U.S. State Department re-issued a travel warning on Friday advising Americans to avoid travel to Kenya, due to what it calls "continuing and recently heightened threats from terrorism and the high rate of violent crime in some areas."
"The U.S. government continues to receive information about potential terrorist threats aimed at U.S., Western, and Kenyan interests in Kenya, including in the Nairobi area and in the coastal city of Mombasa," said the warning. "Terrorist acts can include suicide operations, bombings, kidnappings, attacks on civil aviation, and attacks on maritime vessels in or near Kenyan ports."
Many of those involved in the latest attacks remain at large, according to the State Department, though the subsequent investigation and response continues.
Security officials believe al-Shabab targeted the Kenyan mall in retribution for that country's involvement in the African Union Mission in Somalia, which Kenya formally joined in 2012.
Less than two days after the attack on the mall ended, militants attacked a Kenyan security post on the border with Somalia, killing two officers. Three other officers were injured and 11 vehicles were destroyed, according to Al Jazeera.