Moscow stated that the entry ban on nine Canadians was a “retaliatory measure” against the sanctions imposed on Russian officials in March.

Following Canada’s similar measures on the treatment of Kremlin critic Alexey Navalny, Russia announced tit-for-tat sanctions on nine senior Canadian officials, including the attorney general.

The Russian Ministry of Foreign Affairs said in a statement on Monday that the nine Canadians have been barred from entering Russia for “a period of uncertainty.”

The banned Canadians include Attorney General David Lamerty, Warden Anne Kelly, and Canadian Army Intelligence Command Commander Scott Bishop.

Deputy Secretary of Defense Jody Thomas and the head of the Royal Canadian Mounted Police Brenda Luchi and her deputy Brennan were also targeted.

Senior Army official Mike Rullo, Minister of Intergovernmental Affairs Dominique LeBron and Marcy Sukes, a senior official in the office of Prime Minister Justin Trudeau, are also on the list.

Moscow stated that the entry ban was a “retaliation measure” that imposed sanctions on nine Russian officials on March 24.

Canada said at the time that its sanctions were a silent response to “serious” human rights violations and to President Vladimir Putin’s most outspoken domestic critic Navalny.

Navalny is currently serving two and a half years in prison for “violating parole regulations.”

Canada’s sanctions — including Russian officials including Alexander Bortnikov, the head of the powerful Federal Security Bureau (FSB) — include asset freezes.

Navalny imprisonment

Russian opposition figure Navalny was imprisoned when he returned to Russia from Germany in January, where he was treated because the German authorities concluded that he was poisoned with a banned nerve agent in Russia.

The Kremlin stated that it had not seen evidence of his poisoning and that his imprisonment was not political.

The anti-corruption activist announced a hunger strike in March and requested proper medical treatment in prison. Increasing health complaints, Including numbness of the limbs.

On April 20, in a state of increasing weakness after the hunger strike, Navalny was transferred to the prison hospital. The West warned that if he died, he would face serious consequences.

The 45-year-old politician cancelled the strike three days later. On Monday, his team stated that he had been transferred back to Pokrov Prison, 100 kilometers (60 miles) west of Moscow.

Since Navalny returned to Russia, the European Union and the United States have also imposed new sanctions on Moscow.