LAUSANNE, Switzerland — Five Russian race walkers have been suspended for four years after testing positive for EPO.

The sanctions were announced Thursday by the Court of Arbitration for Sport.

The five, including 2013 world championship silver medalist Mikhail Ryzhov, all tested positive for blood-boosting EPO in June 2015 at Russia’s national training center in Saransk.

Also suspended were former European championship medalist Ivan Noskov, Elmira Alembekova, Vera Sokolova and Ivan Noskov.

The sanctions were handled by CAS because the Russian track and field federation is currently suspended.

A World Anti-Doping Agency investigation last year found that athletes and coaches had tried to obstruct drug testers from collecting samples during the out-of-competition controls that caught the five. The Saransk center was then under the control of coach Viktor Chegin, who was banned for life in March. More than 25 of his athletes have failed drug tests.