MOSCOW, July 23. /TASS/. Over 16,800 foreign mercenaries have joined the Ukrainian armed forces since Moscow launched its special military operation, Russian Investigative Committee Chairman Alexander Bastrykin said.

"According to available data, more than 16,800 foreign nationals have arrived in Ukraine since the start of the special military operation, seeking to take part in fighting on the side of the Ukrainian armed forces," he told TASS in an interview ahead of Russia’s Investigative Officers’ Day.

Many mercenaries have been killed, while others have broken their contracts and left Ukraine, Bastrykin pointed out.