At least 59 people were killed and 175 injured in Saturday's attack on a Nairobi shopping centre, the Kenyan interior 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.