A Russian official says the Pulkovo airport in St. Petersburg has been evacuated, reportedly because of a bomb threat.

Anna Fedoseyeva, spokeswoman for the airport in Russia's second-largest, city said on Tuesday the evacuation of passengers and staff began at 3 p.m. local time. She would not say why the airport was evacuated and said she had no information whether any flight into the city have been diverted.

Russian news agencies, citing the company operating the airport, say the evacuation was called following a bomb threat. Local police were not immediately available for comment.

Bomb threats are common in Russia, mostly the work of teenage pranksters, but evacuations of airports or railway stations are rare.