MOSCOW (Reuters) - The southern Russian city of Novorossiisk on the Black Sea declared a state of emergency on Sunday as forest fires spread across an area of 22 hectares, its mayor said.

Intense heat, strong winds and dry thunderstorms have caused forest fires across Russia in recent weeks, from the remote Siberian region of Tuva to the Republic of Sakha, also known as Yakutia, in the Far East.

Pictures published by the mayor of Novorossiisk, Andrei Kravchenko, showed firefighters battling blazes and vast expanses of scorched earth and trees.

Kravchenko, writing on Telegram, said buses had been prepared to evacuate around 200 people from risk areas and that helicopters were extinguishing the blazes across mountainous terrain.

Fires have spread across the broader southern Krasnodar region where Novorossiisk is located, on the Black Sea where many Russian holidaymakers head during the summer months.

(Reporting by Reuters; Writing by Alexander Marrow; Editing by Hugh Lawson)