The group consisted of 11 Belarusian citizens and four Russian citizens. The Border Guard said their use of tourist visas was inconsistent with their declared purpose of stay in Poland.
All 15 received decisions ordering them to leave the country, giving them eight days to depart.
Organisers had received reports that athletes from Russia and Belarus might try to compete despite the ban. They suspected the athletes were hoping to be added to the entry list after arriving in Bielsko-Biała.
Paweł Połtorzecki, president of the Polish Karate Union, said the first warning sign was a Russian national appearing at a refereeing course, which led to the first detention.
The organisers then asked the Border Guard to carry out checks.
The incident occurred during the World Championships for cadets, juniors and under-21 athletes, which ended on Sunday in Bielsko-Biała.
Poland won two medals at the event, with Natalia Bałut taking gold and Michał Przasnyszki winning bronze.
(sp)
Source: TVP.Info