At least 20 people have been killed and more than 400 others injured after a series of large explosions rocked the city of Bata in Equatorial Guinea.

The cause of the four blasts at a military base early on Monday morning (Australian time) was not yet known, with fears the death toll could rise as rescue teams continue the hunt for survivors.

“We hear the explosion and we see the smoke, but we don’t know what’s going on,” local resident Teodoro Nguema told the AFP.

A defence official told television station TVGE that authorities had ruled out an attack on the central African country.

TVGE showed teams pulling people from piles of rubble, some of whom were carried away wrapped in bedsheets. It said 420 people were injured, citing a local health official.

Tweet from @GuineaSalud

Trucks filled with survivors, including children, drove up to the front of a local hospital. Inside, wards were overwhelmed with the wounded.

France’s ambassador Olivier Brochenin expressed his condolences over the four blasts, which he called a “catastrophe”.

Tweet from @O_Brochenin

TVGE called on people to donate blood and said hospitals in the Central African nation were full.

In the blast area, iron roofs were ripped off houses and lay twisted amid the rubble. Only a wall or two remained of most residences.

In the immediate aftermath, people ran in all directions, many of them dazed and screaming.

The Spanish embassy in the capital, Malabo, has requested its nationals to remain at home.

“Following developments in Equatorial Guinea with concern after the explosions in the city of Bata,” said Spanish Foreign Minister Arancha Gonzalez Laya on Twitter.

The blast comes as Equatorial Guinea, an oil producer, is suffering a double economic shock because of the coronavirus pandemic and a drop in the price of crude oil, which provides around three-quarters of state revenue.

-with AAP