NAIROBI, Kenya (AP) — Gunshots rang out from the upscale mall in Kenya’s capital Wednesday morning, the day after the president declared an end to a four-day siege by Islamic militants.

Government spokesman Manoah Esipisu told The Associated Press the shots came from Kenyan forces going room to room in the large Westgate Mall, firing protectively before entering unknown territory.

“During sanitization, once you take control of the place, if you go to a room where you haven’t visited before, you shoot first to make sure you aren’t walking into an ambush,” he said. “But there hasn’t been any gunfire from the terrorists for more than 36 hours.”

But a top security official, speaking on condition of anonymity because of the sensitivity of the information, said even around the time President Uhuru Kenyatta told the nation in a televised address on Tuesday night that “we have ashamed and defeated our attackers,” three shots rang out at the mall.

Kenyatta said Kenyan authorities were still trying to determine where those shots came from.Meanwhile, the Kenyan government said forensic experts from the United States, Britain and Israel would be assisting them in their investigation of the attack.

“The mall is sealed off; it is a crime scene,” Esipisu said.The process of retrieving bodies from inside the mall still had not begun Wednesday morning — possibly indicating that the situation was not yet considered secure — though a city morgue official said his workers were preparing to go into the building soon.

The attack claimed by Somali militant group al-Shabab killed at least 61 civilians, six security officers and five extremists, Kenyatta said. Three floors of the mall collapsed and at least one more militant’s body is believed to be buried in the rubble. Officials said the death count will likely rise. Estimates varied between only a few bodies to dozens of bodies possibly still inside the mall.

Another 175 people were injured, including more than 60 who remain hospitalized.Fears persisted that some of the attackers could still be alive and loose inside the rubble of the mall, a vast complex that had shops for upscale retailers, as well as banks, restaurants and a casino.

A high-ranking security official involved in the investigations said it would take time to search the whole mall before declaring that the terrorist threat had been crushed. That official insisted on anonymity in order to discuss information not publicly disclosed.

Kenyatta declared three days of national mourning beginning on Wednesday.Eleven other suspects have been taken into custody but Esipisu would not comment on what information they may have given to authorities.

“At this at this point, the interrogations are ongoing and I can’t reveal any of the details,” he said.Al-Shabab, whose name means “The Youth” in Arabic, first began threatening Kenya with a major terror attack in late 2011, after Kenya sent troops into Somalia following a spate of kidnappings of Westerners inside Kenya.

The al-Shabab extremists stormed the mall on Saturday, throwing grenades and firing on civilians.The group used Twitter throughout the four-day siege to say that Somalis have been suffering at the hands of Kenyan military operations in Kenya and the mall attack was an act of revenge.

“You could have avoided all this and lived your lives with relative safety,” the group Tweeted Tuesday. “Remove your forces from our country and peace will come.”

The militants specifically targeted non-Muslims and at least 18 foreigners were among the dead, including six Britons, as well as citizens of France, Canada, the Netherlands, Australia, Peru, India, Ghana, South Africa and China. Five Americans were among the wounded.

American officials had not confirmed the deaths of any U.S. citizens but a U.S. Embassy vehicle, identifiable by its numbered diplomatic license plate, arrived at the morgue on Tuesday. It appeared possible the morgue visit was by security officials with an agency like the FBI who were seeking information about one of the bodies inside.

The mall attack was the deadliest terrorist attack in Kenya since a 1998 al-Qaida truck bombing of the U.S. Embassy in Nairobi that killed more than 200.

Security officials in Nairobi always knew that Israeli-owned Westgate mall, which was popular with foreign residents of the capital as well as tourists and wealthy Kenyans, was a likely target for terror attacks.

Associated Press writer David Rising contributed to this story from Nairobi, Kenya.

JEROME DELAY/AP
IN MOURNING: Relatives of Johnny Mutinda Musango, 48, weep after identifying his body at the city morgue in Nairobi, Kenya, Tuesday. Musango was one of the victims of the Westgate Mall hostage siege. Kenyan security forces were still combing through the mall on the fourth day of the siege by al-Qaida-linked terrorists.