At least 39 people were killed during a Saturday afternoon shooting rampage at a shopping mall in an upscale district of Nairobi. The attack is believed to be orchestrated by extremists against non-Muslim Kenyans and Westerners in the area.
At least 150 were also injured, says Kenyan President Uhuru Kenyatta, who also reported the current death toll. He said he lost some family members in the attack
Somali militant group al-Shabaab claimed responsibility on Twitter for the deadly shooting, which was allegedly carried out by five to 10 gunmen with AK-47s and other sophisticated weapons. Al-Shabaab said the attack was retribution for Kenyan forces' 2011 push into Somalia and threatened more violence.
"The Mujahideen entered #Westgate Mall today at around noon and are still inside the mall, fighting the #Kenyan Kuffar inside their own turf," the group said on Twitter.
"What Kenyans are witnessing at #Westgate is retributive justice for crimes committed by their military," the group said.
Americans were among those injured at the Westgate mall shooting, according to a statement from Marie Harf, deputy spokesman for the State Department.
"We have reports of American citizens injured in the attack, and the U.S. Embassy is actively reaching out to provide assistance," she said. "Due to privacy considerations, we have no further comment on American citizens at this time."
The attack began on Saturday afternoon, according to Kenya's Daily Nation. Gunmen tossed grenades and opened fire as panicking shoppers fled the building, some jumping down one story from the second floor of the mall to escape, witnesses told the paper.
Nairobi Police Chief Benson Kibue deemed the shooting "a terrorist attack."
Witnesses told local and national news media that the gunman asked Muslims to leave before opening fire. Kenya is 83% Christian with a sizable Muslim community - about 11% of its 44 million people.
As night fell in Kenya's capital, hostages remained inside the mall, but officials didn't say how many people were held captive. Army special forces troops had moved inside the mall as well.
Off-duty Sgt. Major Frank Mugungu told the Associated Press that he saw four male attackers and one female, and that he could clearly identify one of the gunmen as a Somali, though he could not identify the rest.
Military cordoned off the building in the heart of the upscale Westlands district, which is home to upper-class Kenyans and expatriate Westerners - many of whom work for the United Nations - and a locale frequented by tourists.
A local organization was hosting a party for children at the Israeli-owned Westgate mall on Saturday. The mall is also a popular nightspot for hip, young Kenyans who gather there to watch movies or eat at restaurants there.
It is on Kenya's watch list as a site for attacks, along with its towering conference center and Western hotels such as the Hilton.