WASHINGTON (Reuters) - The United States on Tuesday imposed sanctions on two Russians, one Russian company and one Slovakian company for what Washington said were their actions to help another Russian company avoid sanctions over the country’s malicious cyber-related activities.

FILE PHOTO: National flags of Russia and the U.S. fly at Vnukovo International Airport in Moscow, Russia April 11, 2017. REUTERS/Maxim Shemetov/File Photo

The U.S. Treasury said in a statement that the sanctioned companies, Saint Petersburg-based Vela-Marine Ltd and Slovakia-based Lacno S.R.O., and the two individuals helped Divetechnoservices evade previously imposed sanctions.

In June, the United States sanctioned Divetechnoservices, also based in Saint Petersburg, for procuring underwater equipment and diving systems for Russian government agencies, including Russia’s FSB intelligence agency.

The Obama administration sanctioned the FSB in December 2016, citing the Russian government’s aggressive harassment of U.S. officials and cyber operations aimed at the 2016 U.S. presidential election.

In a statement on the Russian foreign ministry’s website, Russian Deputy Foreign Minister Sergei Ryabkov called the latest sanctions groundless and promised a response from Moscow.

Ryabkov’s criticism extended to separate sanctions Washington imposed on Tuesday on two Russian shipping companies that it said were involved in transferring refined petroleum products to North Korean vessels in violation of Unite Nations restrictions.

The U.S. Treasury said the two individuals targeted on Tuesday under the cyber-related sanctions program, Marina Igorevna Tsareva and Anton Aleksandrovich Nagibin, had both helped Divetechnoservices attempt to circumvent U.S. sanctions.

The head of Vela-Marine told Reuters he did not understand why his company was being designated. Speaking by telephone, Andrei Kuklin, head of the company, said, “Unfortunately I cannot comment. I don’t understand what the problem is.”

Reuters was unable to immediately determine contact information for Lacno, which does not have its own website and which does not list any contact number on the Slovak finance ministry registry of firms website.

Nagibin did not answer a call seeking comment. Reuters was not immediately able to identify contact information for Tsareva.