NAIROBI — Kenyan President Uhuru Kenyatta said security forces have finally defeated a small group of terrorists after four days in fighting at a Nairobi mall.

In a televised address to the nation Tuesday, Kenyatta said “We have ashamed [sic] and defeated our attackers.”

He said the attack had left 240 casualties, including 61 dead civilians and six of his security forces. The president said five terrorists were killed and another 11 suspects have been taken into custody.

The president noted that three floors of the Westgate mall collapsed and that there are “several bodies still trapped in the rubble including the terrorists.”

He also declared three days of national mourning.

Earlier Tuesday, Islamic militants who staged a deadly attack on the Westgate Mall said that 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, an official said.

The Kenyan Red Cross earlier confirmed at least 62 people had 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 have an exact count. The government official insisted on anonymity so he would not face retribution from government officials.

Kenyan forces had 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 issued an assurance that the defense forces were continuing to “neutralize” the terrorist threat.

In a new Twitter feed established earlier Tuesday after previous ones were cut off, the al-Qaida-linked rebel group al-Shabab 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 US Embassy vehicle, identifiable by its numbered diplomatic license plate, arrived at the morgue on Tuesday. American officials have not confirmed the deaths of any US 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-Shabab, whose name means “The Youth” in Arabic, said the mall attack was in retribution for Kenyan forces’ 2011 push into neighboring 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.”