Russia's legendary rifle-designer Mikhail Kalashnikov has been hospitalised in intensive care after complaining of general weakness, his assistant was quoted by news agencies as saying on Tuesday.
The 93-year-old father of the AK-47 has been having heart problems and feeling poorly since March, when he stopped showing up for work, his aide told the RIA Novosti news agency.
"When I visited him at home last week, he told me that nothing seemed to hurt, but that he simply had no strength left," his assistant Nikolai Shklyayev was quoted as saying.
"It seems that this is just his age showing," Shklyayev said.
The assistant said Kalashnikov was sent to intensive care on Thursday after complaining of swelling.
"I last got in touch with (Kalashnikov's) driver. He said that everything was fine," Shklyayev told the Interfax news agency.
Kalashnikov designed his iconic rifles -- staples of armies across the world for the past half century -- at the Izmash factory in the central city of Izhevsk.
Originally formed in 1807, Izmash remains one of the main producers of Russian weapons.
But like several other specialised industrial firms, it has been hit by dwindling post-Soviet demand and its failure to make up for this with foreign orders.
Kalashnikov and 16 colleagues raised the alarm about the situation at Izhmash in an open letter to President Vladimir Putin last month, saying production had fallen to an all-time low and the factory needed to be saved.
According to popular legend, Kalashnikov began designing weapons after having trouble with the rifles the Soviet Red Army was using during World War II.