MOSCOW (AP) -- A Russian opposition leader is in intensive care in a Moscow hospital, and a lack of clarity about the cause of his sudden illness has raised fears of foul play.
The First City Hospital said 33-year-old Vladimir Kara-Murza remained in grave condition Thursday, two days after he was admitted. The Interfax news agency, citing the hospital's chief doctor, said he appeared to be suffering from pancreatitis and double pneumonia.
His father, a prominent journalist also named Vladimir, told Interfax that doctors haven't ruled out foul play, but there was no evidence that his son had been deliberately poisoned.
Kara-Murza was a close associate of opposition leader Boris Nemtsov, who was assassinated in February, and works with a civic organization founded by Mikhail Khodorkovsky, the former oil tycoon and Kremlin opponent.
U.S. Ambassador John Tefft said on Twitter that ""We are concerned about Vladimir Kara-Murza and urge that he receive the best medical care now."