Rome's Fiumicino airport resumed full operations after smoke from a forest fire on Wednesday forced Italy's busiest hub to suspend takeoffs and restrict landings.

Airline Alitalia announced the resumption of services in a Tweet several hours after the blaze broke out in one of several forests of pine trees near the airport.

Forest rangers said in a statement that the blaze had affected about 40 hectares of a nature reserve that totals some 16,000 acres. Whipped by high winds, the fire was brought under control by fire-fighting planes that dropped water on the area.

The blaze "appears" to have been set intentionally and is under investigation, an Interior Ministry official said. It is the second fire to have hindered airport operations since May.

A fire in a terminal on May 7 affected services for more than two months before the airport fully opened on July 17.

Prime Minister Matteo Renzi commented that if the fire was set intentionally, it would be a "very grave" attack on the country's "tourism and economy", according to sources in his office.

Fiumicino is on the Mediterranean Sea, west of the capital. It is close to a number of parks and nature reserves of forests of pines native to the area.

Rome's Fiumicino airport is owned by ADR, a unit of Atlantia. – Reuters