London Zoo has reopened a day after a fire that killed four meerkats and an aardvark.

The zoo said on its website on Sunday that it will operate normally, including visits with Santa. It says fire experts are confident the zoo can operate safely.

The cause of the fire is being investigated after it broke out early on Saturday morning near a cafe and the meerkat enclosure.

Misha the aardvark died in the blaze. (AAP)

Staff and firefighters tried to remove animals from the area as quickly as possible but were unable to rescue Misha, a nine-year-old aardvark, and the four meerkats.

The zoo in central London at the edge of Regent's Park is a popular attraction that often draws heavy holiday crowds.

Some members of the zoo staff were treated for smoke inhalation and shock but there were no severe injuries.

More than 70 firefighters were called to the blaze. (AAP)