At least six people were killed Tuesday when an Islamist suicide bomber and gunmen stormed an upmarket hotel and office complex in Nairobi, sparking an hours-long siege in which scores of terrified people were trapped inside the compound.
Gunshots rang out sporadically late into the night in the capital as police combed the hotel and outlying office buildings for survivors hiding from the gunmen, while trying to flush out the attackers.
The attack at the DusitD2 compound, which includes a 101-room hotel, spa, restaurant, and offices for local and international companies, began at 3:00 pm (1200 GMT) with a massive explosion heard five kilometres (three miles) away at the AFP bureau.
The Al-Qaeda-linked Somali group Al-Shabaab, which carried out a notorious assault on a Nairobi shopping mall in 2013, claimed responsibility for the latest strike, according to the SITE Intelligence Group which monitors jihadist activities.
"We can now confirm that this criminal activity commenced at about three o'clock in a coordinated fashion and began at I&M Bank with an explosion that targeted three vehicles in the parking lot, and a suicide explosion in the foyer of Dusit hotel," said Kenyan police chief Joseph Boinnet.
He said "a number of guests suffered serious injuries" but did not give a figure for fatalities.
An AFP photographer saw the bodies of five dead, slumped over tables on a restaurant terrace in the complex. An official at the MP Shah hospital in Nairobi told Citizen TV seven wounded had been admitted, one of whom had died.
Meanwhile a police source, who asked not to be named, said he had seen as many as 14 dead.
Elite police forces evacuated terrified workers barricaded in offices for up to seven hours after the explosion, which was followed by an hour of sustained gunfire.
A number of heavily-armed foreign forces, who appeared to be from embassies based in Nairobi, were at the scene alongside Kenyan security officers.
'Very confident' attackers
As the operation continued past midnight, it was unclear how many people were still hiding inside office buildings or the hotel, owned by Thailand's giant Dusit Thani Group.
"I can now report we have secured all the buildings ... we are in the final stages of mopping up the area," said Interior Minister Fred Matiangi.
However a fresh spurt of gunfire rang out not long after he spoke, and there were reports of people still trapped.
Simon Crump, who works in the complex, said terrified workers had barricaded themselves inside their offices after "several" explosions.
"We have no idea what is happening. Gunshots are coming from multiple directions," he told AFP a few hours before he was among those evacuated.
One survivor rescued from the building, speaking to a local television station, said the attackers were "very confident; they were people who knew what they were doing".
CCTV footage run on local television stations showed four attackers, clad all in black and heavily armed, entering a courtyard in the compound at the start of the attack.
'A flash and a bang'
John Maingi said there had been "a flash of lights and a loud bang" at the Secret Garden restaurant where he works.
"When I peeped outside I saw a human leg which has been cut off. We hid in the room and then some police officers rescued us," he said.
Reuben Kimani, a barista who was rescued after several hours trapped inside the hotel, said he had recognised one of the attackers as a client he had served coffee to in recent days.
"I knew one of them because he had a big scar on one of his hands," he said. "I saw them. They shot six of my friends, four didn't die but two succumbed."
Shortly after the attack, flames and plumes of black smoke billowed into the sky from the parking lot where several cars where ablaze.
Police sirens echoed through the city and two helicopters buzzed overhead while ambulances with flashing lights lined up outside the hotel.
Other establishments popular with westerners and locals, such as the popular J's and Alchemist bars and the Village Market shopping centre, announced on social media that they had closed for security reasons.
The attack at DusitD2 is the first in Nairobi since gunmen stormed the city's Westgate shopping mall in 2013, killing at least 67 people. The attack and ensuing siege lasted about four days.
That assault was also claimed by Somalia's Shabaab, fighting since 2007 to overthrow the internationally-backed government in Mogadishu.
The Westgate attack resulted in many upscale establishments and shopping centres in the capital -- including the Dusit -- putting up strict security barriers to check cars and pedestrians.
The Shabaab targeted Kenya after it sent its army into Somalia in October 2011 to fight the jihadist group.
On April 2, 2015, another Shabaab attack killed 148 people at the university in Garissa, eastern Kenya.
In its statement, the group noted the attack came exactly three years after its fighters overran a Kenyan military base in Somalia.
"This attack on Nairobi hotel came as Kenyans and their media are commemorating (the) El Adde attack," it said.
The Shabaab claimed more than 200 soldiers died in that assault. The government has refused to give a toll or disclose details.