Lavrov's remarks on July 31 came after former Armenian President Robert Kocharian was charged with violently putting down protests against his successor in 2008.
Kocharian, who was president from 1998 to 2008, was taken into custody on July 27 after being charged over the deadly dispersion of opposition protesters following the disputed 2008 presidential election.
On the same day, Yuri Khachaturov, the Armenian head of the Russia-dominated Collective Security Treaty Organization, was charged, like Kocharian, with overturning Armenia's constitutional order in connection with the deaths of 10 protesters in 2008.
Khachaturov and Kocharian have both denied the charges and claimed they are politically motivated.
"The events of the last few days...contradict the recent declarations of the new Armenian leadership that it was not planning to pursue its predecessors on political grounds," Lavrov said. "Moscow, as an ally of Yerevan, has always had an interest in the stability of the Armenian state, and therefore what is happening there must be of concern to us," he said.
Comment: See also: Crowds flee Ariana Grande concert in Manchester following reports of explosion; at least 22 killed and 59 injured - UPDATES