Eyewitnesses saw armed men in black, their heads covered in scarves, entering the Westgate shopping centre on Saturday afternoon
At least 59 people were killed and 175 injured in Saturday’s attack on a Nairobi shopping centre, a Kenyan government minister has said.
Joe Lenku said 1,000 people had managed to escape from the Westgate centre after the assault by suspected al-Shabab militants.
He added that between 10 to 15 attackers were still in the building.
It is not known how many civilians remain trapped there – either as hostages or hiding from the militants.
There is a heavy military presence both in and around the shopping centre, and sporadic gunfire can be heard from inside.
There are reports that the gunmen are currently holed up in a supermarket.
Kenyan President Uhuru Kenyatta earlier vowed to “hunt down the perpetrators wherever they run to”.
Al-Shabab told the BBC it carried out the attack on the upmarket shopping centre in response to Kenyan military operations in Somalia.
There are about 4,000 Kenyan troops in the south of Somalia, where they have been fighting the militants since 2011.
‘Watching and monitoring’
Kenyan officials said “major operations” were under way with police and soldiers preparing an apparent bid to bring an end to the stand-off.
They said the security forces had finally “pinned down” the surviving gunmen.
Interior Minister Joseph Ole Lenku says the operation at the shopping centre is “very very delicate”
“The work is continuing, but you cannot rush these things,” an army officer posted on the perimeter cordon set up around the mall told the AFP news agency.
“Our teams are there, we are watching and monitoring, we will finish this as soon as we can.”
Al-Shabab has claimed there are at least 36 hostages, but this cannot be independently confirmed and there are also likely to be people hiding away from the attackers.
The authorities have asked journalists to exercise caution when reporting military developments because the gunmen might be monitoring the media.
“Hostiles suspected to have access to the internet,” the Disaster Operation Centre in Nairobi posted on Twitter.
“Reports on personnel movement and progress will not be posted for fear of compromising strategy.”