Mexican authorities now put the number killed in Friday night's oil pipeline blast at 66, with dozens injured.
Initial reports had said that at least 21 died, according to BBC.
It is believed the blast occurred after the line was ruptured by suspected oil thieves in the town of Tlahuelilpan, in Hidalgo state.
Officials say dozens of people had been scrambling to fill up containers when fire broke out on Friday evening.
Footage on local television showed large flames and people at the scene with severe burns.
Fuel theft, known locally as "huachicoleo" (or moonshining) is rampant in some Mexican communities.
The government has said the practice cost the country about $3.0 billion last year.
President Andrés Manuel López Obrador, who took office in December, has launched a major crackdown.
Pemex, Mexico's state-owned petroleum company, said in a statement that the fire was caused by illegal tapping.
Thousands of marines have been deployed to guard pipelines and transport has been shut down altogether in places.
The policy has led to increased reliance on tanker deliveries and there have been widespread reports of fuel shortages and long lines at petrol stations across the country.
Public Security Minister Alfonso Durazo confirmed the blaze had been extinguished shortly before 0:00 local time (06:00 GMT).