The death toll rose to four Wednesday in the deadly oil rig blaze that produced a massive inferno and plume of smoke in the Gulf of Mexico, according to state oil company Pemex.

The fire occurred at a Pemex dehydration and pumping platform known as Abkatun Permanente, located in Campeche Sound on the west side of the Yucatan Peninsula. Initially, Pemex said one contractor was killed and 16 Pemex workers were hurt, including two who were being treated in the hospital in grave condition. Local emergency services, however, said as many as 45 people were injured.

About 300 workers were transferred out of the area while eight boats were brought in to fight the fire, Pemex said.

It was not immediately clear what caused the blaze. Pemex has suffered a number of accidents in recent years, with at least 37 people killed by a blast at the company's Mexico City headquarters in 2013. Another 26 people were killed at a fire in a Pemex natural gas facility in September 2012.

— Jacquellena Carrero and Erik Ortiz, with Reuters