The bus had just set down the last of its passengers at the Fullriggaren housing estate in Malmö's Västra Hamnen (Western Harbour) district when the accident happened.
Police cordoned off a 200 metre radius around the vehicle for safety reasons.
Several eye witnesses told the Sydsvenskan newspaper that they had heard explosions before seeing the burning vehicle.
“The bus really exploded,” Jeanette David, who lives in a nearby building, said. “I live on the third floor and I could still feel the shockwaves through the window.”
“Suddenly there was a loud bang and there was a bus in flames,” said Julia Harryson. “I saw the bus from the balcony and continued exploding and burning furiously. I've never seen anything like it.”
But Peter Hagert, press spokesperson for Nobina, the company that operates the buses for Malmö's city government, told The Local that these reports appeared to be inaccurate.
“I don't think there was an explosion,” he said. “What happened was that one of our buses in Malmö caught fire. Luckily the driver was alone on the bus when it started. He looked back and saw that smoke was beginning to fill up the bus, and he evacuated the bus promptly in line with his training.”
The police cordoned off a 200 metre circle around the bus. Photo: Andreas Hillergren/TT
Hagert said that even if there had been passengers on board, he did not think anyone would have been hurt.
“The progress of the smoke coming onto the bus was not rapid, so even if there had been passengers on the board, the bus driver would have evacuated them,” he said.
He declined to speculate on what might have caused the fire, saying that he expected investigators from Malmö's fire department to complete an official investigation within a couple of days.
The buses' gas tanks, he stressed, were designed so that explosions were unlikely even if one of the buses caught fire.
“They're structured in such a way that they're not supposed to blow up, they're supposed to burn out.”