The United States imposed sanctions on Monday on four more Russians for alleged human rights abuses, including two officials said to be involved in the cover-up of the death of a lawyer who died in prison after exposing large-scale corruption.
Visa bans and asset freezes were also imposed on two senior officials of the Chechen Republic implicated in the kidnapping and torture of a Chechen activist, Ruslan Kutayev, a senior official of the U.S. State Department said.
The US Treasury Department identified the men as Apti Alaudinov, deputy minister of internal affairs of the Chechen Republic, and Magomed Daudov, chief of staff of the Executive Office of Head and Government of the Chechen Republic.
They and Deputy Prosecutor General Victor Grin and Andrei Strizhov, an investigator, were designated under a U.S. law named for Russian lawyer Sergei Magnitsky, who allegedly uncovered tax fraud that involved Russian officials.
"Specifically Grin was responsible for opening two posthumous cases against Magnitsky - they put Magnitsky on trial well after he was dead, which astonished us; we didn't know it was possible," the senior State Department official said.
The addition of the four names raises the number of people sanctioned under the 2012 US Sergei Magnitsky Rule of Law Accountability Act to 34, the official said.
He said the designation of the individuals could provoke Russian retaliation but that the United States was committed to continuing the process.
Russia vowed in May to retaliate against what it called "unfounded" US sanctions imposed under the Magnitsky Act.
Washington has not linked the sanctions to those it has imposed over Moscow's annexation of Crimea and unrest in eastern Ukraine.