The European Union has said that it had summoned the Russian charge d'affaires in Brussels over the death in prison of opposition leader Alexei Navalny.
The EU's managing director for Eastern Europe, Russia and Central Asia, Michael Siebert, summoned Kirill Logvinov and "called upon Russia to allow an independent and transparent international investigation into circumstances of Alexei Navalny's sudden death," said a statement from EU's diplomatic service.
"The EU side conveyed EU's outrage over the death of the Russian opposition politician Alexei Navalny, for which the ultimate responsibility lies with President Putin and the Russian authorities."
It "urged Russia to release his body to his family without further delay and allow the family to organise a funeral".
"Russia must immediately and unconditionally release all other political prisoners, as well as all those detained in cities across Russia when paying tribute to Alexei Navalny," it said.
Mr Navalny, 47, died in a remote Arctic prison last Friday, according to Russian prison authorities.
Belgium, France, Germany and Poland are among the countries that have summoned Russian ambassadors over Mr Navalny's death.
The United States is due to announce fresh sanctions on Russia on Friday over his death.
Navalny's mother calls on Putin to release body
Alexei Navalny's mother has urged Mr Putin to "immediately" release the body of her son in her first comments since his death.
His widow had echoed the call and repeated accusations against Mr Putin over Mr Navalny's death - shortly before her X account was suspended.
Mr Navalny's mother Lyudmila Navalnaya travelled to the remote IK-3 prison colony on Saturday, the morning after his death was announced, and has since been barred from seeing his body.
"I appeal to you, Vladimir Putin, the solution to the issue depends only on you," she said in a video published by his team.
"Let me finally see my son. I demand that Alexei's body be released immediately so that I can bury him in a humane way."
She wore black and stood near the prison colony - one of Russia's harshest - where he spent his last weeks.
"For the fifth day, I cannot see him, they don't give me his body and I am not even told where he is."
Mr Navalny's allies have said the mother has been barred from morgues and was yesterday told by investigators that his body could be kept for "at least two weeks."
Mr Navalny's team also published a written letter by Lyudmila Navalnaya - who is not a public figure - to Mr Putin with the demand.
The Kremlin has refused to say when the body will be handed over and Mr Putin has been silent on the death of his main political opponent.
Its spokesman Dmitry Peskov brushed off Yulia Navalnaya's statement that Mr Putin killed her husband as "unfounded and vulgar".
"I could not give a damn how my words are commented by a press secretary of a killer," Yulia Navanaya shot back on social media.
"Give back the body of Alexei and let us bury him with dignity, do not stop people from saying their goodbyes with him," Yulia Navalnaya said.
Russia detained hundreds of mourners in the days after Mr Navalny's death.
Meanwhile, social media site X has restored access to the account of Yulia Navalnaya, which it had suspended earlier.
Ms Navalnaya had only created the account yesterday and four days after the death of her husband, Russian opposition leader Alexei Navalny.
A message on the @Yulia_Navalnaya account page earlier read: "Account suspended. X suspends accounts which violate the X rules."
It included a link to the site's rules of use but did not provide a specific reason for the account being suspended.
In a nine-minute video message yesterday, Ms Navalnaya said Mr Putin had killed her husband and in doing so had robbed her of a husband and her two children of a father.
However, she said the only answer to such a crime was to continue her late husband's fight for a free and prosperous Russia.
Russians, she said, wanted to live differently, even if there appeared little hope.
"I want to live in a free Russia, I want to build a free Russia," Ms Navalnaya said in the video message entitled: "I will continue the work of Alexei Navalny."
