What you need to know:
- Interior Minister Joseph Ole Lenku said 59 people were confirmed dead, while the Red Cross has estimated the number of injured at around 200.
Kenyan troops backed by Israeli forces battled Sunday to end a siege in an upmarket shopping mall and free hostages held by Somali militants in an attack that has so far killed 59 people.
Sporadic gunfire could be heard as Kenyan security officials said they were attempting to kill or capture the remaining attackers and end the 26-hour-long bloodbath at the Westgate mall.
"The Israelis have just entered and they are rescuing the hostages and the injured," a Kenyan security source told AFP. The Israeli foreign ministry refused to confirm or deny its forces were involved.
Somalia's Al Qaeda-inspired Shebab rebels said the carnage at the part Israeli-owned complex was in retaliation for Kenya's military intervention in Somalia, where African Union troops are battling the Islamists.
Interior Minister Joseph Ole Lenku said 59 people were confirmed dead, while the Red Cross has estimated the number of injured at around 200.
Lenku said there were still between 10 to 15 gunmen in the shopping centre. "We believe there are some innocent people in the building, that is why the operation is delicate."
Kenyan President Uhuru Kenyatta had said in a televised address to the nation late Saturday that he had lost family members in the attack.
"Let me make it clear. We shall hunt down the perpetrators wherever they run to. We shall get them. We shall punish them for this heinous crime," he vowed.
The Westgate mall is popular with wealthy Kenyans and expatriates, and was packed with around 1,000 shoppers when the gunmen marched in at midday Saturday, tossed grenades and sprayed automatic gunfire at terrified people.
Security agencies have long feared that the shopping centre could be targeted by Al Qaeda-linked groups.
The attack was the worst in Nairobi since an Al-Qaeda bombing at the US embassy killed more than 200 people in 1998.
After a day and night of sometimes ferocious gun battles, security sources said police and soldiers had finally "pinned down" the gunmen. The Kenyan Red Cross appealed for blood donations and authorities urged residents to steer clear of the area.
"We are still battling with the attackers and our forces have managed to maroon the attackers on one of the floors," said Kenyan military spokesman Colonel Cyrus Oguna. "We hope to bring this to an end today."
-- Playing dead --
One teenage survivor recounted to AFP how he played dead to avoid being killed.
"I heard screams and gunshots all over the place. I got scared. I tried to run down the stairs and saw someone running towards the top, I ran back and hid behind one of the cars," 18-year-old Umar Ahmed said.
In the hours after the attack began, shocked people of all ages and races could be seen running from the mall, some clutching babies, while others crawled along walls to avoid stray bullets.
"They spoke something that seemed like Arabic or Somali," said a man who escaped the mall and gave his name only as Jay. "I saw people being executed after being asked to say something."
Kenyan police, troops and special forces then moved in and went shop-to-shop. Foreign security officials -- from Israel as well as the United States and Britain -- were also seen at the complex throughout the drama.
An AFPTV reporter said she saw at least 20 people rescued from a toy shop, some of them children taken away on stretchers.
Kenneth Kerich, who was shopping when the attack happened, described scenes of utter 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.
"The gunmen tried to fire at my head but missed. I saw at least 50 people shot," mall employee Sudjar Singh told AFP.
Among the dead was renowned Ghanaian poet and former UN envoy Kofi Awoonor, 78, Ghanaian officials said, while his son was injured.
-- Shebab claim responsibility --
A spokesman for Shebab said the attack was retaliation for Kenya's nearly two-year-old military presence in war-torn Somalia in support of the internationally backed Mogadishu government.
"We have warned Kenya of that attack but it ignored (us), still forcefully holding our lands... while killing our innocent civilians," Shebab spokesman Sheik Ali Mohamud Rage said in a statement.
"If you want Kenya in peace, it will not happen as long as your boys are in our lands."
The group also issued a string of statements via Twitter, one of them claiming that Muslims in the centre had been "escorted out by the Mujahideen before beginning the attack".
Israeli interests in Kenya have come under attack before. In November 2002 there were two simultaneous attacks in the Mombasa area. A missile targeted an Israeli charter flight as it took off from the port city's airport, but missed.
At the same time a car packed with explosives smashed into the Paradise hotel, the only Israeli-owned hotel in the Mombasa area, as Israeli tourists were checking in. Ten Kenyans and three Israelis died.
EU foreign policy chief Catherine Ashton said she was "appalled by the brutal attack against innocent citizens" in Nairobi.
Paris confirmed two French citizens were among those killed in what it condemned as a "cowardly" attack. Canada's Prime Minister Stephen Harper said two Canadians, one of them a diplomat, were among the dead, while official Chinese news agency Xinhua said one Chinese woman was killed and her child wounded.
Two Indians and a South Korean were also among the dead.
The United States said its citizens were reportedly among those injured by the "despicable" act while British Foreign Secretary William Hague said there were "undoubtedly" British nationals caught up in the siege.
The UN Security Council condemned the attack "in the strongest possible terms".