In March 2014 Ukraine started to ban several Russian TV channel from broadcast in Ukraine, followed in February 2015 with a ban on showing (on Ukrainian television) of "audiovisual works" that contain "the popularization, agitation for, propaganda of any action of law enforcement agencies, the armed forces, other armed, military or security forces of the occupier state". One year later Russian productions (on Ukrainian television) had decreased by 3 to 4 (times). In 2015 Ukraine started banning Russian artists from entering Ukraine and banning other Russian works of culture from the country also when they were considered "a threat to national security". (Following the Kerch Strait incident) starting 30 November, Ukraine is banning all Russian men between 16 and 60 from entering the country with exceptions for humanitarian purposes, claiming this is a security measure. As another response to the Kerch Strait incident Ukraine imposed a 30-day martial law period that started on 26 November in 10 Ukrainian border oblasts (regions). Martial law was introduced because Ukrainian President Petro Poroshenko claimed there was a threat of "full-scale war" with Russia.