The Russians were detained under the country's Administrative Code on March 24. Five other Russians, including a prominent television journalist, could face similar fates.
Russian Embassy officials in Belarus earlier said they had visited the seven Russians detained by police during unauthorized rallies in the country's capital.
"Consulate officials have visited all the seven detained citizens of Russia, including [reporter] Pavel Sheremet. The detainees did not make any requests or complaints," a mission representative said, adding that their relatives had been informed about their detention.
The embassy has sent a note to the Belarusian Foreign Ministry, and Russian diplomats are maintaining contacts with the republic's law-enforcement bodies, the diplomat said.
Courts are expected to rule on the other five Russians either later on Monday or Tuesday.
On March 25, crowds protesting the re-election of Belarusian President Alexander Lukashenko clashed with riot police on Minsk's central square. The police detained 300 opposition supporters.
