Niger Republic began three days of mourning on Wednesday after the death toll from a tanker truck explosion rose to 60.
Flags were flying at half-mast as two further deaths were recorded, up from the initial death toll of 58 people earlier, the government said in a statement.
The explosion near a petrol station in the capital, Niamey, happened in the early hours of Monday as some residents were trying to syphon fuel from a tanker that had overturned near the airport.
At least 37 people were injured, some seriously, and brought to hospitals.
The cause of the accident remained under investigation on Wednesday.