Update 8 p.m. EDT: "Two or three” of the al-Shabab gunmen were Americans, said Kenyan Foreign Minister Amina Mohamed. They were described as “young men, about between maybe 18 and 19,” and of Somali or Arab origin.

Original story:

Kenyan authorities are in full control of Westgate mall in Nairobi after a long siege, the Interior Ministry said in tweet Monday night.

“We’re in control of Westgate,” the ministry announced.

“Our forces are combing the mall floor by floor looking for anyone left behind. We believe all hostages have been released,” the ministry added.

Earlier in the day, officials said three attackers were killed in fighting, and more than 10 suspects arrested. Eleven Kenyan soldiers were wounded in the running gun battles.

"Taken control of all the floors. We're not here to feed the attackers with pastries but to finish and punish them," Police Inspector General David Kimaiyo said on Twitter in the early evening.

Interior Minister Joseph Ole Lenku 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, according to the Associated Press.

Before the final battle, Kenyan officials earlier said 62 people had 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. The wounded are estimated around 200.

Kenya believes there are also foreigners among the Somali-led attackers, with military chief Julius Karangi saying they came from all over the world. "We are fighting global terrorism here," he said, without giving their nationalities.

White House deputy national security adviser Ben Rhodes said he had no direct information that Americans had participated in the attack, but expressed U.S. worries.

"We do monitor very carefully and have for some time been concerned about efforts by al-Shabab to recruit Americans or U.S. persons to come to Somalia," Rhodes told reporters travelling with Obama to the United Nations in New York.

Speculation rose about the identity of the attackers. Ole Lenku said they were all men but that some had dressed as women.

Despite his assertion, one intelligence officer and two soldiers told Reuters that one of the dead militants was a white woman. This is likely to fuel speculation that she is the wanted widow of one of the suicide bombers who together killed more than 50 civilians on London's transport system in 2005.

Called the "white widow" by the British press, Samantha Lewthwaite is wanted in connection with an alleged plot to attack hotels and restaurants in Kenya. Asked if the dead woman was Lewthwaite, the intelligence officer said: "We don't know."

U.S. President Barack Obama vowed on Monday to assist his father’s homeland in the aftermath of the bloody assault in Nairobi.

"We stand with them against this terrible outrage that's occurred, we will provide them with whatever law enforcement help that is necessary," Obama said before a meeting with Nigerian President Goodluck Jonathan on the sidelines of the United Nations General Assembly.

The attack "underscores" the need for the international community to work together to fight terror, Obama added.