A fuel tank exploded in Muammar Gaddafi's hometown Sirte killing more than 100 people less than a week after the deposed despot was captured and killed in the city.
"There was an enormous explosion and a huge fire. More than 100 people were killed and 50 others wounded" in Monday night's blast, National Transitional Council commander Leith Mohammed told AFP.
He said the scene was "a heart wrenching spectacle with dozens of charred bodies."
The accidental explosion happened as a crowd of people waited near the fuel tank to fill up their cars.
"We are still unable to put out the fire," said Mohammed, adding that it had been caused by a spark from a nearby electricity generator.
Some of the victims had returned to the town, the last bastion of resistance by Gaddafi loyalists, which fell on Thursday, to inspect the damage to their properties, the NTC commander added.
No building was spared in the weeks of fierce combat backed by daily NATO air strikes that reduced the Mediterranean city to rubble, a ghost town filled with the stench of death, where bodies still littered the streets on Monday.
Some of Sirte's residents, who numbered 120,000 before the conflict, have returned since Thursday to salvage the remains of their personal belongings.
But few are expected to stay.
Human Rights Watch has urged Libya's interim government to probe the killing of 53 people whose decaying bodies were found in Sirte, charging that some of the Gaddafi loyalists appeared to have been executed.
On Tuesday, the rights group raised concerns about the vast stockpiles of unguarded weapons in the area around the city, and called on the NTC to secure these sites to prevent further looting.