The death toll from a gasoline pipeline explosion in central Mexico rose to 98 with another 46 hospitalized by 9:00 p.m. local time Tuesday, Governor Omar Fayad told media, according to CCTV reporter. 

The death toll is feared to rise since most injured are in serious condition, Fayad added. 

It is still unclear exactly how the events unfolded leading up to the Friday blast. Mexico has opened an investigation into the cause of the deadly pipeline explosion, including possible negligence by authorities, the attorney general said Monday. The investigation will include officials from the defense ministry, the police, state oil company Pemex, the Hidalgo state government, and the prosecutor's office.

The massive explosion and ensuing blaze broke out at a pipeline spot in the community of San Primitivo of the municipality of Tlahuelilpan at around 7:00 p.m. local time (0100 GMT), when roughly 700 people gathered around to collect the leaking fuel, according to authorities in the area.

Following the accident, Mexican President Lopez Obrador said he was dismayed by the tragedy and offered his deepest sympathy to the families of the victims. "The most important thing" now was attending to the injured in order to save people's lives, he said.

Chinese President Xi Jinping Sunday sent a message of condolence to his Mexican counterpart Andres Manuel Lopez Obrador over this deadly blast. 

In his message, President Xi mourned the dead and expressed heartfelt sympathies to the bereaved families of the victims and wished the injured a quick recovery. President Xi also said that China is willing to provide assistance.

(With inputs from AFP)