The African Union Commission chairperson Moussa Faki Mahamat on Monday conveyed his condolences to Equatorial Guinea following Sunday's deadly explosions that left at least 31 dead.

The number of those injured in the incident is reported to have hit around 600 as search and rescue operations continue.

"Our deepest condolences to the families of the victims and their loved ones, as well as to the people and government of Equatorial Guinea following the terrible explosions in Bata," Mahamat wrote on Twitter.

The blasts hit a military base in the country's commercial hub, Bata. Officials blame badly stored dynamite along with stubble burning by nearby farmers.

There are fears the death toll could rise further as more victims are believed to still be trapped underneath rubble.