A major fire broke out at Mexican state oil producer Pemex's Salina Cruz refinery on Wednesday after a crude spill, though there were no initial reports of injuries.

The blaze began in the pump house of Salina Cruz, Mexico's largest refinery, on Wednesday morning after the spill, and the company was working to put it out, a Pemex spokeswoman said.

A Pemex spokesman said the fire had not yet reached the massive storage tanks, adding that efforts were under way to prevent that from happening.

It was not immediately clear if the refinery had suspended operations.

Images sent by local emergency workers showed a tall, thick plume of black smoke spewing from towering flames at the coastal refinery in the southern state of Oaxaca.

No one was reported hurt, Pemex said.

An official at the Oaxaca state emergency services said some of the local settlements near the refinery had been evacuated.

The refinery has a capacity of 330,000 barrels per day.

The fire occurred a day after heavy rains prompted the refinery to suspend operations and evacuate personnel.

On Tuesday evening, Pemex had said that it was prepared to safely restart operations, though it was unclear if they had resumed.

(Reporting by Miguel Angel Gutierrez, Ana Isabel Martinez and Anahi Rama; Editing by Jonathan Oatis and W Simon)