Mikhail Kalashnikov, the 93-year-old inventor of the AK-47 assault rifle, has been transported by Russia's Emergency Situations Ministry from Izhevsk to a hospital in Moscow for medical tests.
A Russian Health Ministry official told journalists on June 23 that Kalashnikov's condition is of "moderate severity."
He reportedly suffers from thrombosis of the pulmonary artery.
Kalashnikov was briefly hospitalized in Izhevsk at the end of May.
He has won numerous Soviet and Russian awards for the AK-47, which is one of the most commonly used weapons in the world.
Based on reporting by ITAR-TASS and Interfax