Police said the current death toll was provisional, while the Kenyan Red Cross said 63 people were still listed as missing

Kenyan President Uhuru Kenyatta has announced that a four-day siege by Islamist gunmen of a Nairobi shopping mall was over, with loss of 61 civilians and six members of the security forces.

“We have ashamed and defeated our attackers, that part of our task is completed,” a sombre Kenyatta, who himself lost family members in the assault, said in a televised address to the nation yesterday.

He said “three floors of the mall collapsed, trapping several bodies within the rubble including those of terrorists.”

Police said the current death toll was provisional, while the Kenyan Red Cross said 63 people were still listed as missing.

“Our losses are immense,” the president said, announcing three days of national mourning. "We have been badly hurt, but we have been brave, united and strong. Kenya has stared down evil and triumphed. We have defeated our enemies and showed the whole world what we can accomplish,” he said.

Five attackers had been killed and 11 suspects were in custody. Somalia’s Al Qaeda-linked Shebab rebels said the group carried out the attack in retaliation for Kenya’s two-year battle against the extremists’ bases in the country.

“It’s an eye for an eye and a tooth for a tooth,” the group said on Twitter late on Tuesday night.

In one of the worst attacks in Kenya’s history, the militants marched into the four-storey, part Israeli-owned Westgate Mall at midday on Saturday, spraying shoppers with automatic weapons fire and tossing grenades.

Kenyatta said that “forensic investigations are under way to establish the nationalities of all those involved” amid reports Americans and a British woman were among the insurgents.

There has been growing media speculation at the possible role of wanted British extremist Samantha Lewthwaite, daughter of a British soldier and widow of suicide bomber Germaine Lindsay, who blew himself up on a London Underground train on 7 July 2005, killing 26 people.

The president said intelligence reports had suggested that a British woman and two or three American citizens “may have been involved in the attack”, but that could not yet be confirmed.

Lewthwaite is wanted in Kenya, and is accused of links to the Shebab – although the rebels later “categorically” denied the involvement of any woman in the attack, insisting they had “an adequate number of young men who are fully committed”.

Shebab spokesman Ali Mohamud Rage also threatened further “black days” if Kenya did not bring troops home, warning the siege was just “a taste of what we will do”.