MEXICO CITY, May 23 (Reuters) - A fire at a refinery controlled by Mexican state-run oil firm Pemex and an explosion caused by an illegal pipeline tap injured a total of 13 people, the company said in separate statements Wednesday.

Four workers were injured in a fire at the Lazaro Cardenas refinery operated by Pemex, or Petroleos Mexicanos, in the eastern city of Minatitlan, the company first said.

Three workers suffered burns and a fourth suffered a sprain in the incident late Tuesday, Pemex said.

Production was not affected at the refinery, one of six operated by the firm in Mexico, which has a capacity of up to 285,000 barrels per day, it added.

In the State of Mexico, nine people - including three Pemex workers - were injured after an illegal tap caused a pipeline to explode, the firm said late Wednesday. The Pemex employees were taken to a nearby hospital.

Pemex said it will investigate both incidents.

In February, two people died of injuries in hospital and another three were hospitalized after a fire at the Minatitlan refinery.

Reporting by Diego Ore; Writing by Anthony Esposito; Editing by Tom Hogue

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