One of the Islamist militants who stormed an upscale shopping mall here on Saturday wore a white turban, witnesses said, while others wore black head scarves. Most were in civilian clothes, but a few donned camouflage fatigues. Some carried sophisticated machine guns, and others wielded the AK-47 rifles widely used by African insurgents. Most of the extremists who seized the mall were young and barked orders in English.

On Tuesday, the bloody standoff stretched into its fourth afternoon, despite repeated proclamations by Kenyan officials that they had the crisis under control. Elite Kenyan security forces combed the Westgate Premier Shopping Mall, seeking to capture or kill the militants who remained holed up inside.

Sporadic gunfire was heard and smoke continued to rise from the building. Several militants from al-Shabab, a group allied with al-Qaeda, appeared dug in at the shopping center, determined to fight to the death.

In messages posted on Twitter, the militia said it was still holding hostages, who were “looking quite disconcerted but nevertheless, alive.” Another tweet said: “Mujahideen are still holding their ground #westgate.”

Kenyan officials offered a different account, saying they believe all hostages had been released. “We’re very near the end,” Kenya’s Interior Ministry said on Twitter at noon.

What is al-Shabab, and is it a high priority in the U.S. war on terror? Daveed Gartenstein-Ross of the Foundation for Defense of Democracies explains to On Background’s Nia-Malika Henderson. (The Washington Post)

But dozens of people reported to have been inside the mall remained missing, according to the Kenyan Red Cross. And a Kenyan government spokesman, Manoah Esipisu, described a situation where Kenyan security forces were engaged in combat with the militants.

“One more terrorist of the Westgate siege has been gunned down, bringing the death toll of these terrorists to three,” Esipisu wrote in a tweet. Earlier government statements suggested that as many as four of the militants may have been killed.

But al-Shabab quickly parried Esipisu’s tweet with a taunting one of its own. “None of the Mujahids is dead. . . . Everything under control,” the militia said.

There has been considerable speculation about the identity of the militants and how they managed to pull off a sophisticated assault that killed at least 62 people and kept security forces at bay. Kenyan Foreign Minister Amina Mohamed said Monday that “two or three Americans” and “one Brit” were among the perpetrators of the attack.

She said in an interview with “PBS Newshour” that the Americans were 18 to 19 years old, of Somali or Arab origin and lived “in Minnesota and one other place” in the United States. The British jihadist was a woman who has “done this many times before,” Mohamed said.

U.S. officials said Monday that they were pressing to determine whether any of the assailants were American.

“But at this point we have no definitive evidence of the nationalities or identities of the perpetrators,” said State Department spokeswoman Jen Psaki.

Al-Shabab is a Somali militia. But Gen. Julius Karangi, chief of the Kenya Defense Forces, told reporters that the militants inside the mall were “clearly a multinational collection from all over the world,” though he did not offer details. “We are fighting global terrorism here,” Karangi said.

Neither Mohamed nor Karangi offered specifics about the basis of their assertions.

Stepped-up operations

On Monday, Kenyan security forces, assisted by American, European and Israeli advisers, intensified operations to end the crisis.

Police helicopters hovered over the mall. At midday, loud explosions and sporadic bursts of gunfire could be heard emanating from the shopping center. By late afternoon, large plumes of smoke were rising from the area. A senior Interior Ministry official, Joseph Ole Lenku, said the militants had set fire to one of the mall shops, the Nakumatt supermarket, as a tactical diversion.

Many Kenyans have questioned why it has taken so long to end the siege. Senior Kenyan government officials have said that security forces were being cautious to prevent more civilian deaths. On Monday morning, a spokesman for al-Shabab reportedly threatened that hostages would be executed if security forces stormed the mall. “The mujahideen will kill the hostages if the enemies use force,” Sheik Ali Mohamud Rage said in an audio statement posted online.

The death toll released by the government stood at 62 civilians, with more than 175 injured. It was the deadliest attack in Kenya since the 1998 bombing of the U.S. Embassy in Nairobi. An earlier figure of 69 deaths, provided by the Kenyan Red Cross, was revised downward. Sixty-three people were missing, according to the Red Cross, suggesting that the militants still held hostages inside the mall. Kenyan officials said 10 bodies had been pulled out of the mall over the previous 24 hours, but they did not give details.

Al-Shabab has said the carnage was in retaliation for Kenya sending troops to fight in Somalia, where they remain a key defense for the Western-backed Mogadishu government against the militia.

Ten people in Kenya have been detained in connection with the investigation, officials said.

Ten members of the security forces were injured. “Our resolve to defend our country has never been higher,” Lenku said.

But al-Shabab used Twitter to dispute the government’s assertion that it had seized control of all the floors in the mall. “Our Mujahideen are in full control of #westgate. May Allah bless them,” the militia said late Monday night. Attached to the tweet was a photo showing armed fighters in black head scarves patrolling the top floor of the mall, but it was not clear when the picture was taken.

On Sunday, Twitter postings purportedly from al-Shabab described several of the jihadists as American. But the militant group said Monday — on a different Twitter handle, verified by the SITE Monitoring Service, which tracks statements by extremist groups — that it had not sent the earlier messages. Nor had it released the names or any other details about the attackers, it said.

Western concerns

President Obama said Monday that the United States stood with Kenya’s leadership “against this terrible outrage that’s occurred.”

“We will provide them with whatever law enforcement help that is necessary,” he said.

The U.S. government is contributing “technical support and some equipment to assist Kenyan security forces” in responding to the attack, a State Department official said Monday, speaking on the condition of anonymity. The department said American military personnel based at the U.S. Embassy in Nairobi have been helping the Kenyans.

George Little, a Pentagon spokesman, said that no U.S. troops have been sent to Kenya to provide assistance.

The involvement of the United States, Israel and other countries underscores the West’s concerns about al-Shabab’s reach. Numerous foreigners have joined the militia, Arabic for “the Youth.” Several dozen Americans, many of Somali origin, are among the foreign recruits, according to counterterrorism analysts.

Reports that the gunmen spoke English suggest that they were not natives of Somalia, where citizens generally speak Somali.

The militants were using “big-caliber guns,” said Frank Musungu, a Kenyan army warrant officer who was at the mall when the militants stormed it Saturday. “There was one woman among them. She had an AK-47.”

Foreigners have reached high ranks in the Somali extremist group. One senior field commander, Omar Shafik Hammami, an Alabama native who went by the name Abu Mansoor al-
Amriki, starred in propaganda rap videos to attract Western recruits. He was reportedly killed last month by his comrades after a falling-out with the militia’s top leadership.

The foreign jihadists were the militia’s key link to al-Qaeda’s main body in Pakistan and have been central players in some of the militia’s most gruesome attacks. In September 2009, a Somali American from Seattle drove a truck bomb into an African Union base in Somalia, killing 21 peacekeepers.

Even though many U.S. counterterorism officials and analysts say al-Shabab does not have the capability to strike the United States, some U.S. politicians have voiced concern. Rep. Peter T. King (R-N.Y.), a member of the House Intelligence Committee, said in an interview with ABC’s “This Week” that he assumed that law enforcement agencies are looking at ways to prevent a similar attack in the United States.

“We know there’s probably still 15-20 Somali Americans who are still active over there,” King said. “The concern would be if any of them have come back to the United States and would use those abilities here in the United States.”

Details about the identities of the victims continued to trickle out Monday. They included Kofi Awoonor, a well-known Ghanaian poet, professor and former diplomat; a retired tropical-disease specialist from Peru; the president of a football club in Kenya; a Canadian diplomat; and a 33-year-old Dutch researcher who worked for the Clinton Health Access Initiative and had just earned a degree from Harvard University, according to the Associated Press.

“We lost one of our foundation’s people there, one of our health access workers who was a wonderful Dutch nurse who was in Nairobi because she was about to have a baby,” former president Bill Clinton told “PBS Newshour.” He added: “She and the baby’s father were just strolling through the mall. It’s tragic.”

The father, an Australian architect who works in Africa, also was killed in the attack, the AP reported.

Craig Whitlock, Scott Wilson, Anne Gearan, Ernesto Londoño and Julie Tate in Washington contributed to this report.