Some 14,000 hectares (34,568 acres) have been consumed by about 25 forest fires burning in the Mexican Caribbean state of Quintana Roo, where cities and resort towns, such as Cancun, Playa del Carmen and the state capital, Chetumal, are covered with smoke, officials said.

The more than two dozen fires have mainly affected the cities of Benito Juarez, Lazaro Cardenas, Tulum, Othon P. Blanco, Solidaridad, Jose Maria Morelos and Bacalar, the Quintana Roo state government said.

Nine of the forest fires are burning on the outskirts of Quintana Roo's largest cities, but the blazes do not yet pose a threat to populated areas.

Urban areas in Cancun, Playa del Carmen and Chetumal have been covered by smoke since Saturday, when the blazes intensified.

Some of the fires were started by people clearing land to build residential complexes, Quintana Roo environmental management chief Graciela Saldaña said.

A huge fire is getting closer to the Yum Balam nature preserve in Lazaro Cardenas.

Fighting the fire has been difficult because of its remote location, forcing firefighters to travel to the site in a helicopter.

The Sian Ka'an and Balam Ka'ax nature preserves are also being affected by fires, officials said.