MOSCOW, March 31 (Reuters) - Firefighters are battling to contain a fire at large petrochemicals plant in Russia's Tatarstan region, the local mayor said on Tuesday, and the aviation regulator said that temporary restrictions had been introduced at the local airport.

Nizhnekamskneftekhim, owned by Sibur, makes synthetic rubbers and plastics.

(Reporting by Reuters; Writing by Lucy PapachristouEditing by Andrew Osborn)