Mexican state-run oil company Pemex said in a statement on Wednesday that the blaze erupted overnight on the Abkatun Permanente platform in the oil-rich Bay of Campeche.
"Regrettably, the death of four workers in the accident on the Abkatun A-Permanente platform has been confirmed," Pemex wrote on Twitter.
The firm says that at least two of the injured workers are in critical condition.
Meanwhile, a spokesman for emergency services in the nearby city of Ciudad del Carmen has said as many as 45 people were injured in the blaze.
The blast took place at 3:40 a.m. in the dehydration and pump area of the platform, located off the coast of eastern Campeche state, the ASEA energy safety agency said in a separate statement.