Gunmen holding hostages in a Nairobi shopping mall are reported to have threatened to kill them as Kenyan troops move to end the siege.
In a statement posted on an Islamist website, the Somali Shebaab militants say the hostages will bear the brunt of any force directed against what they call the mujahideen.
The al-Qaeda linked group claims to be in contact with the fighters inside the mall. It also says they are battling both Kenyan and Israeli forces.
As the stand-off enters its third day, sustained bursts of rapid gunfire that lasted 15 minutes have been heard.
AFP news agency correspondents at the scene say this was followed by three big explosions.
A short time ago, the Kenyan authorities said more people have been brought out from the mall and troops are closing in on the militants.
The militants have not said how many hostages are still being held by the dozen-or-so attackers but earlier the Kenyan military said 10 people were being held.
Sixty eight people are known to have been killed in the attack by the Somali group at the Westgate mall in Nairobi on Saturday.
Police warn the death toll could rise sharply as the complex is cleared.
More than 1000 people were evacuated from the mall after the attack began at midday on Saturday. Almost 200 were injured.
The al-Shabaab group opposes Kenya's participation in military operations in Somalia. About 4000 Kenyan troops are in the south of Somalia, where they have been fighting al-Shabaab since 2011.
Military helicopters have been swooping low over the complex and President Uhuru Kenyatta has said security forces intend to "neutralise" the attackers.
The ABC reports Israeli special forces and American FBI agents are working with the Kenyans.
''The criminals are now located in one place within the building," Mr Kenyatta said on Sunday.
"With the professionals on site, we have as good a chance to neutralise the terrorists as we could hope for."
Mr Kenyatta says there are reports of women among the attackers but these could not be confirmed.
The BBC's security correspondent says a security source told him that at least one of the attackers was a woman who appeared to have a leading role.
Some witnesses say the attackers told Muslims to leave the mall and non-Muslims would be targeted.
The ABC reports that sources within al-Shabaab say three of the attackers are from the United States.
The BBC reports Mr Kenyatta's nephew and his fiancee are among the dead. Ghanaian poet Kofi Awoonor has also been killed.
The UK Foreign Office has confirmed three Britons have been killed and says the number is likely to rise.
The ABC is reporting an Australian architect, originally from Tasmania, and his pregnant wife died. French, Chinese, Ghanaian and Canadian citizens are also among the foreigners confirmed killed.
Others are a Chinese woman, two Indians, a South Korean, a South African and a Dutch woman.
One New Zealander has been injured. He has been named as Andrew McLaren.
Mr McLaren works for Olivado, a New Zealand company that has a plant in Kenya. Olivado says he is stable, in good spirits, but will require an operation.