'Today, in Dzhankoy, units of the S-400 Triumph air defence missile system … were put into active service to ensure air defence of Crimea', Rulev told reporters.
The move comes amid an escalation of tensions between Ukraine and Russia after the incident, involving Ukrainian vessels illegally crossing the Russian border at Kerch Strait.
Three Ukrainian ships have provoked an international scandal after they illegally crossed the Russian maritime border and navigated toward the Kerch Strait, the entrance to the Sea of Azov. The vessels were seized by Russia after failing to respond to a demand to stop, with the crews arrested.
Earlier in September, a law enforcement source reported that the fourth battalion of S-400s would be deployed to Crimea near the town of Dzhankoy while the Russian Black Sea Fleet said in a statement that the third battalion of S-400s was put into active service in the Crimean city of Yevpatoria.