FILE PHOTO - Military personnel watch as flames engulf an area after a ruptured fuel pipeline exploded, in the municipality of Tlahuelilpan, Hidalgo, Mexico, near the Tula refinery of state oil firm Petroleos Mexicanos (Pemex), January 18, 2019 in this handout photo provided by the National Defence Secretary (SEDENA). National Defence Secretary/Handout via REUTERS

MEXICO CITY (Reuters) - Mexico’s state oil firm, Pemex, did not close the valve at a leaking gasoline pipeline when first notified because it was not initially thought to be an “important” leak, Mexico’s security minister said on Sunday.

The pipeline in central Mexico exploded on Friday, leaving 85 people dead who were collecting gasoline at the leak, officials said. Security Minister Alfonso Durazo told a news conference that Mexico’s military detected the leak about four hours before Pemex closed the valve.