NAIROBI, Kenya -- Gunmen stormed an upscale shopping mall in Kenya's capital city Saturday, killing dozens of people in a rampage that touched off an hours-long siege by security forces that trapped hundreds, including Americans, inside bathrooms and storage rooms waiting to be rescued.
At least 39 people were killed and 150 people wounded in the siege in Nairobi, Kenya's president, Uhuru Kenyatta, said in a nationally televised midnight speech. He said he had lost family members in the siege.
The death toll was expected to climb. Authorities still had not secured the mall when Kenyatta spoke. Hundreds of people were shopping at midday when the gunmen crashed in, blocking the exits, then throwing grenades and shooting indiscriminately.
Al Shabab, al-Qaida's affiliate in neighboring Somalia, appeared to claim credit for the attack. Kenya declared war on the group in 2011 and sent troops into Somalia after the group was blamed for kidnapping foreign tourists inside Kenya.
"For long we have waged war against the Kenyans in our land, now it's time to shift the battleground and take the war to their land," the group claimed on one of its Twitter accounts.
Saturday's attack on the Westgate shopping mall was the deadliest terrorist incident in Kenya since al-Qaida bombed the U.S. Embassy in Nairobi in August 1998, killing more than 200 and wounding more than 4,000. A bombing that same day at the U.S. Embassy in Dar es Salaam, Tanzania, killed 11 people.
The Westgate mall caters primarily to wealthy Kenyans and foreign residents. The mall has long been considered a prime terror target because of the number of Israeli-owned establishments there and its Western clientele.
But because no attack had been launched since Kenya declared war against al Shabab in 2011, security was generally light, and shoppers rarely expressed concern about the danger. Unlike other exclusive shopping plazas in the city, the Westgate building was not barricaded within a high-walled compound.
Eyewitnesses described the attack as a well planned, coordinated assault in which gunmen armed with rifles and grenades poured out of vehicles and broke into groups. Some gunmen ran through the main ground floor entrance, while at least two others ran up and entered from a top-floor parking lot, trapping shoppers inside.
Rachel Otieno, a hostess at an Israeli-owned restaurant on the ground floor, said the first blast appeared to strike her restaurant's outdoor patio. Then gunfire erupted, and she crawled out into a clothing store.
"The guy behind me was shot," she said. A gunman in a black shirt kept patrolling the ground floor. "To me, he looked Somali," she said.
Others gave hair-raising accounts of hiding in bathroom stalls and cowering on jewelry store floors for hours until security officers arrived to free them.
Lauren, a 34-year-old American from Minnesota who cited work restrictions for asking to withhold her surname, took refuge with 75 others in a back storage room of a large retail store for four hours, ducking behind boxes.
For years, Nairobi has served as a regional base for diplomats, aid workers and businessmen who fly in and out of neighboring countries for work.
"It's going to change how we live here," Lauren said. "We go there several times a week. We all do."
The Saturday attack started around midday local time on an otherwise quiet weekend day in the Kenyan capital. A sudden explosion was swiftly followed by minutes of gunfire and additional explosions. Workers at nearby construction sites gathered on rooftops, staring down from the city's surging skyline on the horrors below.
Minutes after the attack began, a line of cars sat stone still outside the mall. In one lay a woman's corpse. Nearby, a dead man sprawled across the concrete.
Authorities refused to say how many gunmen participated in the attack.
"We don't want to speculate (on) that now," said Joseph Ole Lenku, the Interior Cabinet secretary.
He admitted civilians continued to be trapped inside.
"A number of people have been evacuated. We cannot say that it is 100 percent," he said.
"We have reports of American citizens injured in the attack, and the U.S. Embassy is actively reaching out to provide assistance. Due to privacy considerations, we have no further comment on American citizens at this time," said State Department deputy spokesperson Marie Harf in an emailed statement.
Many of the survivors waited four hours or more for rescue, even as Kenyan security forces released tear gas inside. Eran Ochayon, a 31-year-old Israeli financial trader, raised up his left palm where he had scribbled a verse from the Quran.
The attackers were rumored to be asking captives to recite the verse in an effort to determine who was Muslim.
The hand shook. "I was very sure the shooters were going to come in," he said.
Soon after the attack, worried family members began gathering in the surrounding block, hoping for news of loved ones.
Within the first hour after the attack, a lanky white man in a purple polo shirt paced madly up and down in a parking lot. His voice was strained as he spoke to a nearby Kenyan man who appeared equally distressed.
"Your daughter is in there? My wife is in there," he said, pausing only briefly before continuing to pace back and forth.