NAIROBI, Kenya -- Islamic militants who staged a deadly attack on a Kenya mall said Tuesday hostages are still alive and fighters are "still holding their ground," as Nairobi's city morgue braced for the arrival of a large number of bodies of people killed, an official said.
The Kenyan Red Cross has confirmed at least 62 people have been killed, but spokesman Abbas Gullet said it was still not known how many more may be dead inside the building.
"It is certainly known that there are more casualties," he said.
A government official told The Associated Press that the morgue was preparing for up to 60 bodies, though the official didn't know an exact count. The government official insisted on anonymity so he would not face retribution from government officials.
Kenyan forces have been battling the militants for four days and police said in a tweet: "Troops now in mop up operations in the building."
The police urged people to ignore "enemy... propaganda" and assured that the defence forces were continuing to "neutralize" the terrorist threat.
In a new Twitter feed established Tuesday after previous ones were cut off, the al Qaeda-linked rebel group al-Shabaab said the attack that began Saturday was "far greater than how the Kenyans perceive it."
"There are countless number of dead bodies still scattered inside the mall, and the mujahideen are still holding their ground," the group claimed.
It added that the hostages are "still alive looking quite disconcerted but, nevertheless, alive."
A city resident whose brother is taking part in the military operation inside the mall told The Associated Press that there were many dead bodies in the mall, and a government official said city morgue employees were told to prepare for many bodies.
Both the government official and the Nairobi resident insisted their names not be used so they would not face retribution from government officials.
A U.S. Embassy vehicle, identifiable by its numbered diplomatic license plate, arrived at the morgue on Tuesday. American officials have not confirmed the deaths of any U.S. citizens in the mall attack, but it appeared possible the Americans who visited the morgue -- likely security officials with an agency like the FBI -- could have been seeking information about one of the bodies inside.
Al-Shabaab, whose name means "The Youth" in Arabic, said the mall attack was in retribution for Kenyan forces' 2011 push into neighbouring Somalia. African Union forces pushed the al Qaeda-affiliated group out of Somalia's capital in 2011.
"You could have avoided all this and lived your lives with relative safety," the group Tweeted Tuesday. "Remove your forces from our country and peace will come."
After four days, authorities now say they are involved in a final push to clear out the remaining attackers. But authorities have before referred to their operations as final. And despite the Kenyan government assurances of success, an explosion and gunfire could be heard coming from the mall at around 6:30 a.m., followed by the sustained chatter of automatic weapons for about a minute almost three hours later, according to Associated Press reporters at the scene.
More shots were heard about noontime, followed by two explosions a short time later, and a plane and helicopter circled over the mall.
Security forces carried a body out of the mall, which remained on fire, with flames and smoke visible. A Kenyan soldier wearing bomb disposal protective gear also exited the building.
While the government announced Sunday that "most" hostages had been released, a security expert with contacts inside the mall said at least 10 were still being held by a band of attackers described as "a multinational collection from all over the world."
Kenyan Foreign Minister Amina Mohamed said "two or three Americans" and "one Brit" were among those who attacked the mall.
She said in an interview with the PBS "NewsHour" program that the Americans were 18 to 19 years old, of Somali or Arab origin and lived "in Minnesota and one other place" in the U.S. The attacker from Britain was a woman who has "done this many times before," Mohamed said.
U.S. officials said they were looking into whether any Americans were involved. State Department spokeswoman Jen Psaki said Monday that the department had "no definitive evidence of the nationalities or the identities" of the attackers.
Britain's foreign office said it was aware of the foreign minister's remarks, but would not confirm if a British woman was involved.
The security expert, who insisted on anonymity to talk freely about the situation, said many hostages had been freed or escaped in the previous 24-36 hours, including some who were in hiding.
However, there were at least 30 hostages when the assault by al-Shabaab militants began Saturday, he said, and "it's clear" that Kenyan security officials "haven't cleared the building fully."
Kenyan government spokesman Manoah Esipisu said the country's president would make an address to the nation later in the day but said he could give no immediate details on the operation.
Kenyan security officials on Monday evening said they had claimed the upper hand as flames and dark plumes of smoke rose above the Westgate shopping complex for more than an hour after four large explosions.
Kenya's Interior Minister Joseph Ole Lenku said the evacuation of hostages had gone "very, very well" and that Kenyan officials were "very certain" that few if any hostages were left in the building.
But with the mall cordoned off and under heavy security it was not possible to independently verify the assertions. Similar claims of a quick resolution were made by Kenyan officials on Sunday and the siege continued. Authorities have also not provided any details on how many hostages were freed or how many still remain captive.
Three attackers were killed in the fighting Monday, Kenyan authorities said, and more than 10 suspects arrested. Eleven Kenyan soldiers were wounded in the running gun battles.
Al-Shabaab spokesman Sheik Ali Mohamud Rage said in an audio recording posted on a militant website that the attackers had been ordered to "take punitive action against the hostages" if force was used to try to rescue them.
A Western security official in Nairobi who insisted on not being named to share information about the rescue operation said the only reason the siege hadn't yet ended would be because hostages were still inside.
Westgate mall, a vast complex with multiple banks that have secure vaults and bulletproof glass partitions, as well as a casino, is difficult to take, the official said. "They are not made for storming," he said of the labyrinth of shops, restaurants and offices. "They're made to be unstormable."
Some 12 to 15 al-Shabaab militants attacked Saturday, wielding grenades and firing on civilians inside the mall, which includes shops for such retail giants as Nike, Adidas and Bose and is popular with foreigners and wealthy Kenyans.
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. Nearly 200 people were wounded, including five Americans.
Fighters from an array of nations participated in the assault, according to Kenya's Chief of Defence forces Gen. Julius Karangi. "We have an idea who these people are and they are clearly a multinational collection from all over the world," he said.
The attack at the Westgate mall in Nairobi's Westlands neighbourhood was the deadliest terrorist attack in Kenya since the 1998 al Qaeda truck bombing of the U.S. Embassy in Nairobi, which killed more than 200 people.
Associated Press reporters Rodney Muhumuza, Ben Curtis, David Rising, Adam Schreck and Jacob Kushner in Nairobi, Kenya, Cassandra Vinograd in London, and Abdi Guled in Mogadishu, Somalia, contributed to this report.
