Charred remains of dozens of people were seen in photos circulating across social media, along with a video of a large crowd collecting liquid from puddles in yellow jerry cans.
A fuel tanker exploded in eastern Tanzania on Saturday, killing at least 62 people, authorities said, as flames ripped through a crowd that had gathered to siphon petrol from it.
Video clips circulating on social media showed the charred remains of dozens of young men and burnt motorbikes. In footage from before the explosion, a large crowd was collecting liquid from puddles in yellow jerry cans.
"The fire was huge and it was challenging to rescue victims. I have seen about 65 to 70 people being rescued because the fire was fast spreading across the accident area," witness Daniel Ngogo said.
"The situation is really bad. Many people died here, even those who were not stealing fuel because this is a busy place."
Government spokesman Hassan Abbasi said at least 60 people died and 70 were injured in the blast, which occurred in Morogoro, a town around 200 km west of the commercial capital, Dar es Salaam.
The government was helping coordinate the salvage operation "to ensure we bury the bodies ... relatives identify the bodies of their loved ones, and those injured get proper treatment," he added, in comments broadcast live by a state TV channel.
President John Magufuli was "shocked and saddened" by the accident, his office said in a statement.
"We have been saddened by reports of an accident involving a fuel truck in Morogoro, which caught fire and burnt several people," government spokesman Hassan Abbasi said on Twitter.
Tulanana Bohel has more from Dar es Salaam.