An ally of jailed Kremlin critic Alexei Navalny has urged Navalny to end his hunger strike, which is in its third week.
"To continue [the strike] would be dangerous for his life and health," Anastasia Vasilyeva, head of the Doctors Alliance union, told Reuters. "We very much hope Alexei will end the hunger strike tomorrow."
The news comes a day after more than 1,900 Navalny supporters were detained during protests in cities across the country.
In a Thursday Instagram post, Navalny said he felt "pride and hope" after learning about the protests.
"Here it is - the salvation of Russia. You. Those who came out. Those who didn't come out but supported it. Those who didn't support it publicly, but sympathized," Navalny wrote.
On Sunday, Navalny, whose health reportedly is deteriorating, was moved from a penal colony east of Moscow to the hospital at a prison in Vladimir, which is 180 kilometers east of Moscow.
Kremlin critic Alexei Navalny stands inside a defendant dock during a court hearing in Moscow, Russia, Feb. 20, 2021, in this still image taken from video. (Press Service of Babushkinsky District Court of Moscow/Handout)
On Monday, Russia's prison service said Navalny's condition was "satisfactory," but another one of his physicians, Dr. Yaroslav Ashikhmin, said Navalny was suffering from high levels of potassium, which could cause a heart attack, and increased creatinine levels, showing potentially weakened kidney function.
Navalny, 44, began his hunger strike at the end of March to protest what he said was a lack of medical care for severe back and leg pain.
Navalny survived a near-fatal poisoning last year and was arrested when he returned to Moscow in January following lifesaving treatment in Germany. The Kremlin denies any role in the poisoning.
He was sentenced to two-and-a-half years in prison in February on an embezzlement charge and was being held at the Pokrov correctional colony, which he described as "a real concentration camp."
The United States and other countries have sanctioned Kremlin officials over the poisoning, and many are calling for Navalny's release.
As Navalny's health deteriorates, Russian authorities have asked the Moscow prosecutor's office to declare Navalny's organization, the Foundation for Fighting Corruption, an extremist organization.