From the first moments of the attack on Nairobi's Westgate mall, information on the attackers and the victims has been sparse.

How many?

Eyewitnesses have described seeing between six and 16 attackers enter the mall on Saturday afternoon. It is thought that between 10 and 15 fighters were involved, but they may have split up into smaller groups as they moved through the multi-storey building.
Kenyan security forces say they have 11 suspects in custody, after they were arrested at the airport, and that another five suspects are dead.
But as a search of the building continues, officials say that more attackers could still be recovered from the rubble. Gunshots were heard at the mall on Wednesday, but Kenyan government spokesman Manoah Esipisu said this was from police firing "protectively", rather than from terrorists and a security source told Reuters that it would take some time to search the whole mall - and to rule out the terrorist threat.

Are they British?

The Somalia-based al-Shabaab has claimed responsibility for the attack. But the group is known to have attracted members from all over the world.
A 35-year-old British man was arrested at the Jomo Kenyatta International Airport on Monday in connection with the attack, as he attempted to board a Turkey-bound flight
The man has been named as Abdulrazak Sharif Ahmed by Kenya's Citizen TV, and was apparently holding a British passport. Reports say he arrived at the airport with bandages on his face.
Britain's Foreign Office confirmed that a British man was arrested as he tried to leave the country. But a spokesman said he was not linked to the attack and British authorities are understood to be trying to make contact with him, to see if he needs assistance. "Our understanding at this stage is that he is not connected to the recent terrorist incident," said the spokesman.
President Uhuru Kenyatta also said that intelligence reports had suggested that "two or three" American citizens may have been involved in the attack.
News

The woman question

Eyewitnesses said the attackers were armed, dressed in black and wearing turbans. And Frank Musungu, an army officer shopping in Westgate who was one of the first to give his account of event, raised one of the biggest questions still surrounding the militants: was a woman involved?
"One of them wrapped a white turban on his head. They were very young and the woman appeared to be lethal," he told Kenyan paper the Nation.
Mr Esipisu said on Wednesday that officials were still investigating whether this was the case: "We have got multiple witnesses saying that they saw a woman.... the forensics will be able to conclusively say whether in fact there was a woman or there wasn't."
For its part, Al-Shabaab told Channel 4 News that no women were involved in the attack, as did the Kenyan interior minister Ole Lunka on Monday, who added that some of the men may have been dressed as women. However he later said it was possible.
Kenya's Foreign Minister Amina Mohamed has also said that a British woman was among the militants, which added fuel to speculation that Samantha Lewthwaite, or the "white widow", was involved.
The 29-year-old from Buckinghamshire, who was married to 7/7 bomber Jermaine Lindsay, is known to be in east Africa and is already wanted by Kenyan police, for her connections with al-Shababb.
But while a British security source has not ruled out her involvement in the Westgate siege, there is no concrete evidence as yet.

Are they from al-Shabaab?

Al-Shabaab quickly put themselves forward as perpetrators of the Westgate mall attack, and have waged a propaganda war against Kenyan officials on Twitter throughout the siege. Their first message read: "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."
Kenyan police for their part have urged media - and others - to "ignore" al-Shabaab's messages, including a claim on Wednesday morning from the al-Qaeda linked group that Kenyan officials used chemical gas against them.
Although no other suspects have been mooted, Kenyan officials said they are witholding final judgement about the perpetrators until the investigation is complete.
Mr Esipisu said they would not release further information "until we have finished the forensic investigation of the bodies, until we can completely say we have identified the nationalities of who is involved, where they came from, who they are." He added: "But they are terrorists and, as we have said, they may be al-Qaeda, they maybe al-Shabaab. They are terrorists."