ROME, July 3 (RIA Novosti) - The death toll in a gas explosion at a railroad station in northern Italy has risen to 20 people after a man and a woman with severe burns died in a hospital overnight, a local health spokesman said on Friday.

A powerful explosion occurred late on Monday in the town of Viareggio when a 14-carriage freight train carrying liquefied petroleum gas (LPG) derailed and two carriages exploded, creating a fireball that engulfed nearby homes, destroying at least two houses.

At least 50 people were injured, and around 20 people remain in hospitals in critical condition, with doctors fighting to save their lives.

Cleanup operations around the station finished on Thursday and emergencies officials began to allow some of the hundreds of residents evacuated after the accident back to their homes.