Masks with the names of the victims of the attack on Garissa University College are displayed during a memorial concert in downtown Nairobi on April 14, 2015
Nairobi (AFP) - All four gunmen from Somalia's Al-Qaeda linked Shebab who carried out the Kenyan university massacre earlier this month were Kenyans themselves, reports said Thursday.
The militants attacked the university in the northeastern town of Garissa on April 2, lining up non-Muslim students for execution and killing 148 people in what President Uhuru Kenyatta described as a "barbaric medieval slaughter".
The fact that all four are reported to be Kenyans highlights the Somali insurgents' ability to recruit within Kenya.
One of the four gunmen killed by Kenyan special forces who ended the day-long siege has already been named as Abdirahim Abdullahi, an ethnic Somali Kenyan national who was a top student and law graduate.
Kenya's Daily Nation newspaper, quoting unnamed intelligence reports, said the other three gunmen killed were also Kenyan and were believed to be from the port city of Mombasa and the far western district of Bungoma.
"Identities will be confirmed once their fingerprints are matched," the Nation said, citing intelligence officials.
There was no immediate response from Kenyan police to confirm the report.
A $215,000 (200,000 euro) bounty has also been offered for alleged Shebab commander Mohamed Mohamud, a former Kenyan teacher said to be the mastermind behind the attack.
The report comes amid concern at a string of measures Kenya has introduced to boost security that rights groups warn could harm innocent Somalis or hamper counter-terrorism efforts.
- Home grown militants -
Kenyan Vice-President William Ruto said last week that "the way America changed after 9/11 is the way Kenya will change after Garissa".
Measures include demands for the world's largest refugee camp complex at Dadaab to be shut and the repatriation of hundreds of thousands of Somalis by July, which the UN warns would have "extreme humanitarian and practical consequences" and would violate international law.
Other actions include the freezing of the money transfers that are a lifeline for many in Somalia, the suspension of two Muslim civil rights groups and a proposed 700-kilometre (435-mile) security fence between Kenya and Somalia.
After the attack, Kenyatta warned that the terrorists were "deeply embedded" inside Kenya, not just Somalia.
Kenyan youths this week began digging a ditch to kickstart construction of a security barrier along the vast and porous border with neighbouring Somalia, although critics have said the huge fence will be unfeasible.
The government has given no details of the construction, cost or how long it will take to complete the fence, which would separate Kenya's northeastern ethnic Somali region from Somalia itself.
Nairobi has also frozen key money transfer companies vital for impoverished Somalia, sparking warnings by aid agencies that the move will hit the poorest hardest.
It has also suspended two key Kenyan Muslim civil society organisations for suspected Shebab links, which rights groups say will damage efforts to counter extremism.
While the Shebab emerged as a Somali Islamist group in 2006 in Mogadishu, they have recruited across the wider region.
The group has carried out a string of revenge attacks in neighbouring countries, notably Kenya and Uganda, in response to their participation in the African Union force fighting them in Somalia.
Following the attack the Shebab warned of a "long, gruesome war" unless Nairobi withdraws its troops from Somalia, saying the gunmen carried out the Garissa attack in revenge for the "systematic persecution of the Muslims in Kenya".