The Somali militant group al-Shabab says its fighters are still holding hostages inside the Kenyan mall where gunmen began a deadly siege on Saturday.
The group said in a series of Twitter messages
Tuesday that militants were "holding their ground" at the Westgate shopping center in Nairobi, and that a "countless" number of dead bodies were inside.
Kenya's military says it is conducting "mop up" operations at the site, while the police urged people to ignore what it called al-Shabab's "propaganda."
The military says three Kenyan soldiers died and 11 others are hospitalized from injuries sustained in the Westgate operation.
Earlier, officials had said they were in control of the mall with soldiers going through the building looking for anyone still inside, and that all of the hostages had been freed.
Fresh gunfire was heard around dawn Tuesday and twice more later in the day. The Kenyan Interior Ministry maintains the operation is "near the very end."
Al-Shabab repeated its stated reason for staging the attack, posting Tuesday that "peace will come" to the mall when Kenya removes its forces from Somalia. Kenya has rejected that demand.
Kenyan forces entered neighboring Somalia two years ago to help rout al-Shabab, which has been fighting to turn Somalia into a conservative Islamic state. Al-Shabab militants often crossed the border to stage attacks in Kenya.
At least 62 people have died in the siege that began Saturday when gunmen stormed the busy shopping mall. Gun battles between Kenyan security forces and the militants have killed three of the gunmen and wounded 11 soldiers. Authorities say at least 10 suspects have been arrested.
The dead include nationals from Britain, Canada, China, France, Ghana, India and South Korea.
Kenyan officials say they believe the gunmen include fighters from several nations. Foreign Minister Amina Mohamed told the PBS Newshour that two or three Americans of Somali or Arab origin and a British national took part in the attack.
White House spokesman Ben Rhodes said the U.S. has long been concerned about al-Shabab recruiting Americans to Somalia, and that the government is examining reports they were involved in the mall siege.
U.S. President Barack Obama said he has spoken directly with Kenya's President Uhuru Kenyatta, and will provide whatever law enforcement assistance Kenya needs.
Obama said he is confident Kenya will rebuild. He called it one of Africa's most stable democracies.
President Kenyatta vows to stand firm against terrorism and punish those behind the attack "swiftly" and "very painfully." The president said his nephew and the young man's fiancee were among those killed.
Smoke rises from the Westgate Mall in Nairobi, Sept. 25 2013.
Catholic nuns pray near the Westgate Mall in Nairobi, Sept. 25, 2013.
Fresh graves of Westgate Mall shooting victims in a cemetery in Nairobi, Sept. 25, 2013.
Kenyan security forces stand on the top floor of a building facing the Westgate Mall in Nairobi, Sept. 25, 2013.
Mary Italo, center, grieves with other relatives for her son Thomas Abayo Italo, 33, who was killed in the Westgate Mall attack, as they wait to receive his body at the mortuary in Nairobi, Kenya, Sept. 25, 2013.
Kenya Defense Forces soldiers take their position at the Westgate Mall, on the fourth day since militants stormed into the mall, in Nairobi, Sept. 24, 2013.
Heavy smoke rises from the Westgate Mall in Nairobi, Sept. 23, 2013.
Paramedics run outside the Westgate Mall in Nairobi after heavy shooting, Sept. 23, 2013.
People donate blood for people injured in the attack at the Westgate Mall, at Uhuru Park in Nairobi, Sept. 23, 2013.
Stephen, center, who lost his father in Saturday's attack at the Westgate Mall in Nairobi, Kenya, is comforted by relatives as he waits for the post mortem exam at the city morgue, Sept. 23, 2013.
Women carrying children run for safety as armed police hunt gunmen at the Westgate Mall in Nairobi, Sept. 21, 2013.
Civilians who had been hiding inside during the gun battle manage to flee from the Westgate Mall in Nairobi, Sept. 21, 2013.