“All activists have arrived in front of the investigative committee of St. Petersburg to be familiarised with the decision,” Xinhua quoted Andrei Suchkov as telling the Interfax news agency.
By Wednesday afternoon, 16 activists had received formal resolutions closing their cases. The committee was expected to issue resolutions to the rest by the end of the day.
All non-Russian activists would then be free to leave the country, their lawyer said.
The activists were detained Sep 19 by Russian authorities after attempting to stage a protest on an Arctic oil drilling platform.
The cases were dropped in conjunction with an amnesty granted this month to about 25,000 prisoners by the State Duma, or lower house of parliament.