The toll was confirmed on Thursday night by the IMSS public health service, reports Efe news.
Eleven injured in the blast remain hospitalised at IMSS institutions in the capital city and Hidalgo state, the service said in a statement.
The explosion and an ensuing blaze occurred at a pipeline spot in the community of San Primitivo in Tlahuelilpan in the evening of January 18.
According to the local government, between 600 and 800 people gathered at the site to collect leaked fuel with containers when the explosion took place.
Stealing fuel from pipelines owned by state oil company Petroleos Mexicanos (Pemex) and re-selling it in the black market has become a major criminal enterprise in Mexico.
This form of theft has cost Mexico some $3.4 billion last year, according to official figures.
The accident is one of the worst tragedies caused by pipeline explosions in Mexico in recent years.
In December 2010, 30 people were killed and 52 others injured in a series of explosions at two oil pipelines in the state of Puebla.