MOMBASA - Radical Kenyan Muslim cleric Aboud Rogo Mohammed, who was on US and UN sanction lists for allegedly supporting Somalia's Al-Qaeda-linked Shebab militants, was shot dead Monday, his wife said.

"A car behind us aimed at my husband, they shot him on the right side," said his widow Haniya Said, screaming in grief after the shooting in the Kenyan port city of Mombasa.

Witnesses said the car was riddled with bullets. A photograph released by his supporters showed his bloody corpse slumped behind the wheel of a car.

"He died as we rushed him to hospital. Why have they killed my dear husband?" Said said, before she and her children were taken to the hospital.

Thousands of angry protestors gathered in Mombasa following Mohammed's killing, blocking off streets around the mosque where he had often preached, setting fire to vehicles and chanting slogans in his support.

Others reported running battles with the police.

A police source confirmed Mohammed had been killed.

"He has been shot dead, he was in a vehicle with his family including wife and children when they were attacked," the source told AFP. Regional deputy police chief Joseph Kitur confirmed a shooting incident, but gave no further details.

Mohammed was placed on a US sanctions list in July for "engaging in acts that directly or indirectly threaten the peace, security or stability of Somalia", specifically for recruiting and fundraising for the hardline Shebab.

The United Nations Security Council placed a travel ban and asset freeze on the cleric in July, saying he had provided "financial, material, logistical or technical support to Al-Shebab".

He was the "main ideological leader" of Kenya's Al Hijra group, also known as the Muslim Youth Center (MYC), the UN said in July. The group is viewed as a close ally of the Shebab in Kenya.

Mohammed "used the extremist group as a pathway for radicalisation and recruitment of principally Swahili-speaking Africans for carrying out violent militant activity in Somalia," the UN said.

MYC leader Sheikh Ahmad Iman Ali, in a message posted on Twitter, said: "We are on the right track when our leaders get shahadah (martyrdom)."

"He will remain in our hearts forever," the MYC added.

Another message offered the grim warming that the "kuffar (unbelievers) will pay" for his death.

Mohammed had "repeatedly called for the violent rejection of the Somali peace process" the US said, noting he had often advocated the use of violence against both the UN and the African Union force battling the Shebab in Somalia.

He "urged his audiences to travel to Somalia to join Al-Shebab's fight against the Kenyan government" the US Treasury said.

Kenyan police arrested the preacher in January, seizing firearms, ammunition and detonators, later releasing him on bail.

He was previously acquitted of the 2002 bombing of an Israeli-owned hotel near Mombasa which killed 15 people -- 12 Kenyans and three Israelis -- as well as three suicide bombers.

The cleric is also alleged to have introduced Fazul Abdullah Mohammed -- the late head of Al-Qaeda's east Africa cell, shot dead last year in Somalia's war-torn capital Mogadishu -- to at least one of the men who helped him carry out the twin US embassy bombings in 1998.

The bombings in Nairobi and Dar es Salaam killed 224 people.

Mohammed, born on Kenya's Lamu island, was aged between 43 and 52, according to different aliases.

Source: AFP