LONDON — Russians responsible for the abduction and indoctrination of Ukrainian children have been sanctioned by the U.K. government.

Britain’s Foreign Office on Wednesday sanctioned 11 groups and individuals based on intelligence assessments it said had found that Russia is seeking to eradicate Ukrainian culture through re-education camps.

U.K. Foreign Secretary David Lammy said the Kremlin’s policy was “despicable” and demonstrated the “depths of depravity” that Russian President Vladimir Putin will go to as part of his invasion of Ukraine.

The U.K. government said more than 19,500 Ukrainian children have been forcibly transferred or deported to Russia and the territories it occupies in Ukraine — while other estimates suggest the total number could be as high as 35,000. Only 1,592 are thought to have been returned, according to Ukrainian government assessments.

Ukrainian intelligence claims to have identified more than 150 locations where children are being held, stretching from the Ukrainian occupied territories, Belarus, and inside Russia.

Last month it was reported that Russian authorities in Ukraine’s Luhansk region had created an online catalogue of Ukrainian children categorized by age, eye and hair color for adoption. Children were advertised with character traits such as “obedient” or “non conflictive.”

The U.K. government’s latest package of sanctions include the Akhmat Kadyrov Foundation, which runs re-education programs and Valery Maiorov, the head of the state-funded Teenage Programs Center, in addition to Russian ministers thought to be responsible for abduction policies.

Lammy said Wednesday: “To take a child from their home and seek to forcibly erase their heritage and upbringing through lies and disinformation can never be tolerated. No child should ever be a pawn of war and that is why we are holding those responsible to account.”