So far, attacks on ships in the Black Sea have not shaken early bookings for next year's tourist season, said Hristina Slavova of the Burgas Regional Tourist Chamber (BRTK). If the attacks continue, she said, the season will be affected.

Bookings for the summer have started, but there are few so far. Tour operators are not getting worried enquiries, and demand is expected to peak in December and January.

Prices of packages for next year may rise slightly, by 2% to 5%, but Slavova said it is too early to give exact figures. Her colleagues in the industry plan to keep this year's price levels and will probably add a little because of market conditions.

"The industry is not inclined to raise prices sharply and ahead of time for the next season," Slavova said. She said the reason is that visitor numbers in the past season stayed at the level of the year before.

The tourism industry is watching how the situation develops and how the government responds.