TLAHUELILPAN/MEXICO CITY, Mexico — Mexico’s new government knew a pipeline was leaking but did not act for hours before a blast killed at least 89 people, a minister said on Sunday, increasing scrutiny of a push to stop fuel theft seen as the president’s first crackdown on crime.

State oil firm Pemex did not close the gasoline pipe when first notified by the military, about four hours before Friday’s blast, because it considered the leak “minimal,” Security Minister Alfonso Durazo told a news conference.

Pemex had been in a rush to reopen the pipeline to avoid a new round of gasoline shortages in Mexico City, said Gonzalo Monroy, the head of Mexico-based energy consulting firm GMEC, citing conversations with oil industry professionals.

Disputing accounts that fuel thieves opened up the pipe, he said sources in Pemex indicated the fissure occurred at a spot Pemex had previously repaired, and gave way under the pressure of a new surge of fuel.

Pemex officials decided to keep fuel running after the first signs of a leak, and send a team to inspect it, he said.

Pemex did not respond to requests for comment.

When questioned about why it took so long to close the pipe’s valves after the leak was detected, Durazo said Pemex followed protocol. The explosion occurred half an hour after Pemex closed the valve, he said, because high-octane gasoline remained in the pipe.

Lopez Obrador said on Sunday that the disaster had not weakened his resolve to fight fuel theft. “I won’t take a single step backwards,” he said at the first of two news conferences. “I can only offer people apologies, if this action causes sacrifices, harm and inconveniences.”

Lopez Obrador said he hoped supply would normalize soon as Mexico buys more tanker trucks for distribution by road.

If successful in uprooting a parallel fuel network that siphons off about $3 billion worth of fuel from Pemex each year, the veteran leftist who won last year’s election on promises to root out endemic corruption will have scored a big early victory, strengthening ailing national oil company Pemex and helping stabilize fuel prices. The blast, however, has raised the stakes.

Failure would likely not only erode his popularity but pose risks for the economy, the world’s sixth-biggest fuel market.An opinion poll last week showed the fuel strategy was a polarizing issue, with about half the population supporting the measure despite the lines at gas stations and other difficulties.

Pemex initially took the Tula-Tuxpan pipeline out of service in late December as the government tried to protect it from gangs who had hit it 10 times in Tlahuelilpan, Pemex Chief Executive Officer Octavio Romero said on Saturday.

After Pemex began attempting to restart operations on Wednesday, the line experienced four more attacks.

Romero said Pemex closed a valve at the pipeline on Friday after noting a drop in pressure from the leak. Pemex informed other authorities of the leak at 4:50 p.m., he added.

Responding to questions about why fuel kept flowing from the leak up until the explosion, Lopez Obrador said that 10,000 barrels of gasoline were accumulated in the pipeline between the Tula refinery and the village. Energy Minister Rocio Nahle said the pipeline was pressurized.

Lopez Obrador said the army, which deployed just 25 soldiers before the explosion, gave orders for villagers to stay back, but were ignored. — Reuters