Kenyan authorities are expected to find dozens more victims than initially feared after the president declared an end to the four-day siege of a Nairobi shopping mall by al Qaida-linked terrorists.

Officials said the death count could soar by another 60 or more.

"We have ashamed and defeated our attackers," President Uhuru Kenyatta said in a televised address to the nation that was delayed for hours as gun battles persisted at the upmarket Westgate mall. "Kenya has stared down evil and triumphed."

Despite Mr Kenyatta's declaration, troops remained deployed at the vast complex and security officials said attackers with weapons or booby traps might still be inside.

A plan to remove bodies was aborted because of continued skirmishes inside the mall, where three floors had collapsed.

Describing the victims as "innocent, harmless civilians" of "various nationalities, races, ethnic, cultural, religious and other walks of life", a solemn-looking Mr Kenyatta reported the known death toll: at least 61 civilians, along with six security forces and five al-Shabab militants.

About 175 people were injured, including 62 who remained in hospital, he said, acknowledging that "several" bodies remained trapped in the rubble, including those of terrorists.
But another government source said a far higher toll was feared and mortuary staff were preparing to receive up to 60 more bodies and a Western embassy official said the number of additional dead could go as high as 100.

"They're just seeing dead bodies. They've found no survivors, no live hostages," said a Nairobi resident whose brother was taking part in the military sweep inside the mall.
Mr Kenyatta said 11 suspects had been arrested; authorities previously announced that seven had been taken into custody at the airport and three elsewhere. "These cowards will meet justice as will their accomplices and patrons, wherever they are," an emotional Mr Kenyatta declared.

"We confronted this evil without flinching, contained our deep grief and pain, and conquered it. As a nation, our head is bloodied, but unbowed."

Mr Kenyatta declared three days of national mourning starting today.

He said forensic experts would examine the assailants' bodies to determine their identities, softening earlier assertions by Kenya's foreign minister that Americans and a Briton were involved in the siege.

"Intelligence reports had suggested that a British woman and two or three American citizens may have been involved in the attack," the president said. "We cannot confirm the details at present but forensic experts are working to ascertain the nationalities of the terrorists."

Kenyan officials as early as Sunday evening began declaring near-victory over what they said were 10 to 15 attackers, some who wore black turbans and many with grenades strapped to their vests. But battles inside the shopping complex continued, straining the credibility of victory declarations.

Booming explosions on Monday collapsed a second-storey car park down into a department store - blasts that set cars on fire and sent dark plumes of smoke skyward for nearly two hours. Explosions continued throughout yesterday and the sound of gunfire from inside the building could be heard. Fresh smoke rose from the building in the afternoon.

Fears persisted that some of the attackers could still be alive and loose inside the rubble of the mall, a vast complex that had shops for retailers like Bose, Nike and Adidas, as well as banks, restaurants and a casino.

Two Kenyan soldiers who had been inside the mall shortly before the president spoke said the operation was mostly over, but security forces were still combing the facility and had not definitively cleared all the rooms.

Another higher-ranking security official involved in the investigations said it would take time to search the whole mall before declaring that the terrorist threat had been crushed.

Al-Shabab, whose name means "The Youth" in Arabic, first began threatening Kenya with a major terror attack in late 2011, after the country sent troops into Somalia following a spate of kidnappings of Westerners inside Kenya.

The group used Twitter throughout the four-day siege to say Somalis had been suffering at the hands of Kenyan military operations in Kenya, and the mall attack was revenge.

"You could have avoided all this and lived your lives with relative safety," the group tweeted yesterday. "Remove your forces from our country and peace will come."

Al-Shabab also denied that any women had attacked the mall. "We have an adequate number of young men who fully committed and ready to sacrifice their lives for the sake of Allah and for the sake of their religion," said the al-Shabab press office in what is thought to be an authentic email address.

The militants specifically targeted non-Muslims, and at least 18 foreigners were among the dead, including six Britons, as well as citizens from France, Canada, the Netherlands, Australia, Peru, India, Ghana, South Africa and China. Five Americans were among the wounded.

The mall attack was the deadliest terrorist attack in Kenya since the 1998 al Qaida truck bombing of the US embassy in Nairobi, which killed more than 200 people.

Al-Shabab claimed Kenyan government forces used explosives in carrying out "a demolition" of the mall, burying 137 hostages.

It also said that "having failed to defeat the mujahideen inside the mall, the Kenyan government used chemical gas to end the siege."

A government spokesman immediately denied the claim, saying that no chemical weapons were used and that the official civilian death toll remains 61. He says three floors of the building collapsed after a fire started by the attackers caused structural weakness.