Norway has accused Russia of being behind a cyber attack that had targeted its Parliament this summer
On August 24, the Storting - Norway's unicameral parliament - was the target of a "vast" computer attack, but Parliament did not specify the origin.
The cyber-attack allowed perpetrators to access and download the emails and data of "a small number of MPs and employees".
"On the basis of the information in the possession of the government, we believe that Russia is behind this activity," Foreign Minister Ine Eriksen Søreide said on Tuesday.
"This is a serious episode that affects our most important democratic institution", Søreide said in a statement, without providing further details.
But the Russian embassy in Oslo has vehemently rejected the accusations as "serious provocation".
"No evidence is presented. We consider such accusations against our country unacceptable," the embassy said in a statement.
"We consider this to be a serious, deliberate provocation, destructive to bilateral relations."
The embassy also said it was waiting for "explanations" from Norway.
"Millions of cyber attacks are annually committed from abroad to Russian state Internet resources ... but this does not give the right to indiscriminately blame the authorities of the countries of their possible origin."
Norway's allegation comes during a time of increasingly strained relations with Russia after the Nordic country expelled a Russian diplomat on suspicion of spying in August.
Russia retaliated by expelling a Norwegian diplomat days later.
Meanwhile, in their annual risk assessment report in February, the Norwegian internal intelligence services warned against operations "on the computer network" which, according to them, constitute "a persistent and long-term threat to Norway".
"The Government will continue its efforts to strengthen our digital security nationally, and strengthen cooperation internationally," said Foreign Minister Søreide.
"The security and intelligence services are cooperating closely to deal with this matter at the national level."