Russia confirmed that its decision to expel a Swedish Embassy employee in Moscow was a retaliatory move. The Foreign Ministry said Tuesday the decision had been taken in response to Sweden’s “unfriendly” gesture against a Russian diplomat in Stockholm.

"This step was taken in response to the Swedish authorities’ unfriendly acts against a diplomat of the Russian Embassy in Stockholm," the Russian news agency Tass quoted the ministry. "What causes bewilderment is that the Swedish side, which has carried through this unfriendly act, now talks about the negative impact of what has happened on the Russian-Swedish relations."

The ministry added that Stockholm should be held entirely responsible for the consequences of the “provocation.”

Swedish Foreign Ministry spokesman Johan Tegel said Russia’s decision will harm relations between the two countries. The Swedish Foreign Ministry confirmed Monday that Russia had expelled one of its diplomats. The identity of the senior diplomat was not disclosed.  

Tegel indicated to Swedish broadcaster SVT that the diplomat had been expelled for "acts improper to his post and status." The Los Angeles Times reported that the term was diplomatic shorthand for espionage.

The Swedish government recently declared persona non grata a Russian diplomat, saying the diplomat’s behavior which had been inconsistent with diplomacy, another reference to spying.

Sweden has been on edge over suspected submarine incursions from Russia.