On Friday morning, officials had counted 56 bodies in mortuaries as searching continued and three days of national mourning were announced.
“In the accident, 108 people were injured, 96 of whom are still being kept in for treatment at Tete Provincial Hospital,” government spokesman Mouzinho Saide said at a press conference in Maputo.
“The cabinet has created a commission of inquiry to investigate the circumstances, causes and responsibilities for this accident.”
Authorities suggested that residents may have been taking petrol after the vehicle had crashed or been abandoned by drivers who fled when they feared it could explode.
Photographs from the hospital in Tete showed badly burned children arriving for emergency care.
“Of the people brought in, we have two pregnant women, 17 children, and a total of 45 severe injuries, with cases of third-degree burns,” Jose Mendonca, Tete provincial government spokesman, told reporters late Thursday.
Hospital staffing has been reinforced to help deal with the large numbers of injured.
“We do not yet have a definitive idea about the original source of the fire,” said Mendonca.
One local journalist told AFP the truck had crashed on Wednesday and exploded on Thursday afternoon as scores of people tried to syphon off fuel.
The government in Mozambique, one of the world’s poorest countries, recently increased the price of fuel after the value of the local currency — the metical — fell sharply.
The metical has collapsed by 70 percent against the US dollar this year after falling 36 percent in 2015.
The Tete provincial government has appealed for emergency food aid and transport assistance for affected families.
National mourning will be from Saturday until Monday.