Masked gunmen stormed an upmarket mall in Nairobi Saturday and sprayed gunfire on shoppers and staff, killing at least six, before holing themselves up in the complex with hostages.
Police were going shop-to-shop to evacuate terrified people from the Westgate, which is popular with wealthy Kenyans and expatriates and generally packed on weekends.
The attackers sprayed gunfire inside the four-storey mall, causing a huge panic before police units moved in to secure the compound's exits and the situation evolved into a standoff.
"They have seven hostages, confirmed," a police officer told AFP at the scene as security forces were trying to secure a multi-screen cinema complex.
An AFP reporter said she saw at least 20 people rescued from a toy shop on one of the upper floors of the mall. Dozens of wounded, some of them bleeding children, were stretchered away from the mall.
A shop manager who managed to escape said at one point "it seemed that the shooters had taken control of all the mall".
Shocked people -- black, white and Indian -- could be seen running away from the Westgate centre clutching children while others crawled along walls to avoid stray bullets.
The motive of the attack was not immediately clear, but Kenyan media said the attackers, who witnesses said were black-clad and masked, may have been either armed robbers or "terrorists".
The mall -- which has several Israeli-owned businesses, is a hub for Nairobi-based Westerners and one of the foremost symbols of Kenya's affluent classes -- has long been considered a potential terror target.
Kenneth Kerich, who was shopping when the attack happened, described scenes of panic.
"I suddenly heard gunshots and saw everyone running around so we lied down. I saw two people who were lying down and bleeding, I think they were hit by bullets," he said.
"Initially we thought it is police fighting thugs. But we could not leave until when officers walked in, shot in the air and told us to get out."
An AFP television journalist saw three bodies laid out in front of the mall, their heads covered, and two more bodies inside.
An eyewitness who survived the assault by gunmen said he saw the body of a child being wheeled out of the mall.
"The gunmen tried to fire at my head but missed. At least 50 people were shot. There are definitely many casualties," mall employee Sudjar Singh told AFP.
"I saw a young boy carried out on a shopping cart, it looked like he was about 5 or 6. It looked like he was gone, he was not moving or making any noise."
Vehicles riddled with bullet holes were left abandoned in front of the mall as police instructed residents of the Westlands neighbourhood to stay away.
"Our officers are on the ground carrying out an evacuation of those inside as they search for the attackers who are said to be inside," Inspector General of Police David Kimaiyo said.
"We have managed to evacuate some people to safety. We urge Kenyans to avoid the area as we pursue the thugs," Kenya's interior ministry said on Twitter.
The Westgate mall, which opened in 2007, has restaurants, cafes, banks, a large supermarket and a cinema that attract thousands of people every day and have made it a Nairobi landmark.
It is popular with the large expatriate community living in the residential neighbourhoods around it, including with foreign staff from the United Nations, which has its third largest global centre nearby.
Security agencies have regularly included the Westgate shopping centre on lists of sites they feared could be targeted by Al Qaeda-linked groups.
The Somali insurgents from the Shebab group have repeatedly threatened to strike at the heart of Kenya in retaliation for Nairobi's military involvement alongside the government they are trying to overthrow.