Eye witnesses told the Nation the explosion went off shortly after 7pm, getting pedestrians off guard.
Nation reporters saw a hole of about 50 centimetres near the store where the explosion is said to have occurred.
The injured were rushed to the Mother and Child Hospital in Eastleigh.
The police cordoned off the area as they tried to unravel the now horrifying pattern of bomb blasts in the area.
It was not immediately clear what caused the explosion, but eye witnesses claimed it may have been caused by gas cylinder.
Nairobi Area Police boss Moses Ombati told reporters that one of the injured was unconscious and in a critical condition.
He added that seven others had minor injuries.
Mr Ombati added that the police were yet to know the cause of the explosion.
The store lies on a walkway that is usually packed in the evenings with pedestrians rushing back home.
Eastleigh area has been synonymous with explosions in the recent months that have led to injuries and deaths.
Last month, a passenger minibus exploded after a man hurled a bomb in it killing seven people.
The incident followed another one weeks earlier in which an explosion went off in a crowd of pedestrians walking home and killing three.
source: nation.co.ke
source: nation.co.ke
