The group, Good Friends, said all the dead perished in flames when the pipeline blew up in Sonchon county in North Pyongan province on June 9.

"Informed sources told us about 110 people were killed in the blast," Noh Oh-Jae, a group official, told AFP. She refused to further identify the sources.

Noh said the disaster occurred when villagers gathered around a previously cracked pipeline to collect gasoline.

"Someone ignited a flame by mistake, causing a huge explosion that sent flames and smoke billowing up, engulfing people," she said.

Officials at the South's spy agency, the National Intelligence Service, and the unification ministry said they could not confirm the report.

Good Friends said the pipeline carried gasoline from a petrochemical plant at Pihyon, near the border with China, to Taedong county west of Pyongyang.