The UK on Wednesday announced sanctions targeting six people at the helm of the Russian Arctic penal colony where late opposition leader Alexei Navalny died. 

UK says it will hold those behind Navalny's treatment 'accountable' 

"It's clear that the Russian authorities saw Navalny as a threat and they tried repeatedly to silence him... no one should doubt the oppressive nature of the Russian system," British Foreign Secretary David Cameron said.

"Those responsible for Navalny's brutal treatment should be under no illusion — we will hold them accountable," the statement added.   

The individuals targeted by the punitive measures include Vadim Konstantinovich Kalinin, who managed the "Polar Wolf" penal colony where Navalny languished.

The UK said in the statement announcing the sanctions that Navalny was not only denied medical help while in prison, but also forced to walk in extremely cold weather.  

The UK earlier summoned Russia's ambassador on Friday following the news of Navalny's death. 

Western countries pile on sanctions after Navalny's death 

Navalny was the foremost opposition leader against Russian President Vladimir Putin. The 47-year-old was serving a total of over three decades behind bars when he died. 

The EU and the US this week are unveiling new sanctions on Russia not only due to Navalny's death, but also to coincide with the 2-year annivesary of Russia's war on Ukraine. 

The exact cause of Navalny's death is still unclear. The Russian government has criticized Western backlash over Navalny's passing, saying other countries are interfering in its domestic affairs.      

wd/msh (Reuters, AFP)