Residents of the city are urged to donate blood.
TV images show injured and dead being pulled out of landslides after the explosions.
It is not known what is behind the events, but a representative of the Armed Forces tells the TV station TVGE that the authorities have ruled out that it is an attack.
At the military base, military special forces and the paramilitary gendarmerie are stationed.
With its 800,000 inhabitants, Bata is the West African country's largest city.