NAIROBI, Kenya -- Four thunderous explosions rattled Nairobi's upscale mall Monday, part of a battle between Kenyan troops and al-Qaida-linked terrorists. Top Kenyan officials said two hostage takers, part of "a multinational collection from all over the world," had been killed.
Kenya's interior minister said the evacuation of hostages "has gone very, very well" and that Kenyan officials are "very certain" that there are few if any hostages left in the building.
Interior Minister Joseph Ole Lenku also revised the death toll to 62. Kenyan officials earlier said 59 people have died since the siege on Westgate Mall began on Saturday, while the Red Cross had put the toll at 68, then in a tweet lowered it to 62, saying some bodies had been counted twice.
Dark plumes of smoke rose from the mall for more than an hour after four large explosions rocked the upscale Westlands neighborhood. A person with knowledge of the rescue operation told The Associated Press that the smoke was rising up and out of a large skylight inside the mall's main department and grocery store, Nakumatt, where goods like mattresses may have been lit on fire.
Kenya Chief of Defense forces Gen. Julius Karangi said fighters from an array of nations participated in the attack claimed by al-Shabab, a Somali group allied with al-Qaida.
"We have an idea who these people are and they are clearly a multinational collection from all over the world," he said.
Karangi said Kenyan forces were in charge of all floors inside the mall, though terrorists could still be hiding inside. Earlier witness reports had indicated that a woman was among the estimated 10 to 15 attackers. Lenku said that instead some male attackers had dressed up like women.
The four explosions were followed by volleys of gunfire, then a thick, dark column of smoke that burned for roughly 90 minutes. Military and police helicopters and one plane circled over the Nairobi mall, giving the upscale neighborhood the feel of a war zone.
On Sunday Kenyan officials announced that "most" hostages had been rescued. But no numbers were given. Kenyan officials have never said how many hostages they thought the attackers had, but have said preserving the hostages' lives is a top priority, greatly complicating the final fight against the attackers.
Kenyans and foreigners were among those confirmed dead, including British, French, Canadians, Indians, a Ghanaian, a South African and a Chinese woman. The UK Foreign Office said Monday it has confirmed the deaths of four British nationals.
From neighboring Somalia, spokesman Sheik Ali Mohamud Rage for al-Shabab -- the militant group that claimed responsibility for the attack -- said in an audio file posted on a website that the hostage takers had been ordered to "take punitive action against the hostages" if force was used to try to rescue them.
At the Oshwal Centre next to the mall, the Red Cross was using a squat concrete structure that houses a Hindu temple as a triage center. Medical workers attended to at least two wounded Kenyan soldiers there on Monday.
Al-Shabab said on a Twitter feed, an account that unlike some others appears to be genuine, that the attackers had lots of ammunition. The feed said that Kenya's government would be responsible for any loss of hostages' lives.
A large military assault began on the mall shortly before sundown on Sunday, with one helicopter skimming very close to the roof of the shopping complex as a loud explosion rang out, far larger than any previous grenade blast or gunfire volley. Officials said the siege would soon end and said "most" hostages had been rescued and that officials controlled "most" of the mall. But on Monday the standoff remained.
As the crisis surpassed the 48-hour mark, video taken by someone inside the mall's main department store when the assault began emerged. The video showed frightened and unsure shoppers crouching as long and loud volleys of gunfire could be heard.
The al-Shabab extremists stormed the mall on Saturday from two sides, throwing grenades and firing on civilians.
Kenyan authorities said they would do their utmost to save hostages' lives, but no officials could say precisely how many people were being held captive. Kenya's Red Cross said in a statement, citing police, that 49 people had been reported missing. Officials did not make an explicit link but that number could give an indication of the number of people held captive.
Al-Shabab said the attack, targeting non-Muslims, was in retribution for Kenyan forces' 2011 push into neighboring Somalia.