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." In an interview with the US TV programme PBS Newshour, Amina Mohamed said the Americans were 18 or 19 years old, of Somali or Arab origin, and lived "in Minnesota and one other place". Ms Mohamed appeared to contradict earlier comments from Kenya's interior minister, who suggested that all the attackers were men - though some may have been dressed as women. They refused to address reports that Somali-Americans were involved in the attack and said they had little information about who may have been involved. FOREIGN FIGHTERS 
 
 Kenyatta said he could not confirm intelligence reports of British and American militants, adding that forensic tests were being carried out to establish their nationalities. 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.  NAIROBI, Kenya — Authorities said they were going floor by floor through a darkened, smoldering mall early Tuesday as they searched for remnants of a team of attackers that had seized the building, and that they believed all those trapped or held hostage had been freed. Similar claims of a quick resolution were made by Kenyan officials on Sunday and the siege continued. The BBC understands from official sources that six of the attackers have been killed - three on Monday and three since midnight. It is known to have recruited Americans, Europeans and other foreigners, including Kenyans. Kenyan armed forces chief Gen. Julius Karangi said the fire was started by the assailants as a diversion in a bid to flee the building, but provided no more detail. There are about 4,000 Kenyan troops in the south of Somalia as part of an African Union force supporting Somali government forces.  NAIROBI As Kenya began three days of mourning on Wednesday for at least 67 people killed in the siege of a Nairobi mall, it was unclear how many more hostages may have died with the Somali Islamist attackers buried in the rubble. Home to the largest Somali community in the United States, the Twin Cities has been a recruiting ground for ­Al-Shabab, an Al-Qaida-linked extremist Islamic group that has taken responsibility for carrying out the attack on the Westgate Mall in Nairobi. Fletcher said religious leaders who might have encouraged radicalization may be less likely to be outspoken about recruitment to Al-Shabab because of the FBI’s investigation and successful federal ­prosecutions. They are not ­Muslims.” 
 
 Vigorous recruitment 
 
 In what the FBI has said is one of the largest efforts to recruit Americans to a foreign terrorist group, at least 20 men have left Minnesota since 2007 to join the organization.
– Is the siege of Nairobi's Westgate Mall finally near an end? Kenyan authorities say they believe all the hostages have been released, but journalists from the AP and Reuters heard yet more gunfire and explosions as the Kenyan military moved through the building. Officials say the military is going from floor to floor and room to room in the darkened building searching for surviving militants, the Los Angeles Times reports. Somalia's al-Shabab militant group tweeted early today that its fighters "are still holding their ground" and their captives are "still alive, looking quite disconcerted but, nevertheless, alive." In other developments: Kenya's foreign minister told PBS Newshour last night that two or three Americans were involved in the attack. She said they were of Arab or Somali origin, 18 or 19 years old, and had lived "in Minnesota and one other place" in the US. She said a British woman who had "done this many times before" was also involved, contradicting another minister's statement that all the attackers were men. Security officials and soldiers told Reuters that a white woman was among the attackers killed, though they couldn't confirm whether she was Samantha Lewthwaite, the al-Shabab-linked widow of a British terrorist. The State Department says that it is investigating reports that Americans were involved, but "at this point we have no definitive evidence of the nationalities or identities of the perpetrators," the Washington Post reports. Witnesses say most of the attackers were young and shouted to each other in English. British officials say they will not discuss the identity of the attackers while the investigation continues, reports the BBC. Officials say at least six attackers have been killed and around 10 more captured. The civilian body count stands at 62, but the Red Cross says 63 people are still unaccounted for. In Minnesota, home to America's largest Somali community, Muslim leaders refused to comment on reports that Somali Americans were involved in the attack but spoke firmly against extremism, the Star Tribune reports. The attackers "do not represent any religion, they do not represent any community, they do not represent any nationality," one imam said. "They are an organized group of criminals who have conspired to kill and destroy innocent lives. They are nothing but criminals. They are not ­Muslims."