The explosion tore through the depot in the village of Primorskoye on Wednesday afternoon. The blaze was put out late at night and detonations stopped.
"The latest estimate is 60 injured, including two children. The majority received light to moderate injuries. Two or three people were seriously hurt but there is no risk to their lives," Rustam Zantaria said late on Wednesday.
The official added that the majority of those hurt were holidaymakers taking mud baths at a nearby hot Sulfur spring. They received cuts from shrapnel, glass shards and rocks that the blast wave carried.
The Russian Embassy in Abkhazia said on Facebook that 35 Russian tourists had been injured in the blast, 27 of them required hospitalization.