NAIROBI, Kenya -- Kenyan security forces killed three assailants from an Al Qaeda-linked Somalia militia after unleashing a major assault to end the standoff at a shopping mall here, defense officials said.

With the crisis at the Westgate shopping center in its third day, officials said 10 suspects had been arrested for questioning, including two at the Nairobi airport.

The big unanswered questions concerned the number of people held by the gunmen, and their welfare, after Shabab militants threatened to kill hostages if there was an assault.

Kenyan Interior Minister Joseph Ole Lenku said only that efforts to release the hostages were "very, very successful" and those being held were "very few."

Police officials said some hostages were released Monday, but there was no word on how many, or where they were taken.

Lenku told reporters that the number of dead stood at 62, and that 50 of the 175 injured were still being treated in hospitals. A Defense Ministry spokesman said 10 bodies had been recovered from the mall in the previous 24 hours. It was not clear whether they were all included in Lenku's toll.

The Kenya Red Cross had previously reported that 69 people were killed, but later revised the toll to 62, saying some bodies had been double-counted.

The assault by security forces began with weapons fire ringing out at dawn Monday. After sporadic shooting, the attack reached a crescendo in the early afternoon, with a volley of explosions and heavy arms fire. Black smoke poured out of the building, as a fire raged for several hours.

Kenyan armed forces chief Gen. Julius Karangi told reporters that the fire was started by the assailants as a diversion, in a bid to flee the building. Officials said the building was surrounded and that there would be no escape for the terrorists.

Kenyan officials earlier said that 10 to 15 gunmen were involved in the attack.

Karangi said the militants came from different countries. Shabab, the group that has claimed responsibility for the attack, is known to have recruited foreigners, including Americans and Europeans, to fight in Somalia. It has also recruited Kenyans.

"We have an idea who these people are and they're clearly a multinational collection from all over the world," Karangi said.

He also said that security forces were in control of all floors at the mall and were searching the building to ensure no gunmen were hiding. The gunfire continued after he spoke.

Kenyan officials posted upbeat updates on Twitter throughout the day.

"Spread some love, hug a friend, hug a stranger, we're Kenya," ran one tweet from the Interior Ministry.

"We're increasingly gaining advantage of the attackers," Kenyan police chief David Kimaiyo said Monday. "Thumbs up to our multi-agency team, we have just managed to rescue some hostages."

He later tweeted, "Taken control of all the floors. We're not here to feed the attackers with pastries but to finish and punish them."

Around lunchtime, as the operation suddenly intensified, armed personnel carriers and soldiers moved in. Ambulances were on the scene, and fire trucks also moved in as the smoke thickened.

There was a lull, but another intense barrage of fighting broke out inside the building in the late afternoon. Journalists outside the mall were asked to lie down and take cover. 

Police used tear gas to disperse crowds who had gathered not far from the Westgate facility on Monday.