A series of explosions in Brazzaville, the capital of Congo Republic, killed at least four people and injured nearly 60 others, a senior Congolese official said, giving the first toll from Sunday's blasts.

Lots of buildings have been destroyed ... There are four dead and nearly 60 injured, some seriously, Betu Bangana, head of protocol in the presidency, told Reuters by telephone.

Witnesses and state media said the blast occurred during a fire in the arms depot in the Regiment Blinde base in the riverside Mpila neighbourhood. No explanation has been given for the fire.

(Reporting by Jonny Hogg; Writing by David Lewis; Editing by Sophie Hares)