The quake struck the Irkutsk Region at 10:35 local time (01:35 GMT) with the epicenter near Lake Baikal, where it measured over 7 on the Richter scale. Tremors were also felt in other Siberian regions, a regional seismological center in Irkutsk said.
A pulp mill located at the lake, and mini-submarines involved in an expedition to explore the depths of the world's oldest lake were unaffected.
Preliminary reports said in Irkutsk, power and communication supplies were damaged. Minor cracks appeared in the walls of several residential buildings and two hospitals.
Half of the power lines running along a hotel-lined highway linking the city and Baikal, the world's largest freshwater lake and a popular tourist destination, were put out of action. Other damage reports are being verified, local officials said.
Power workers are trying to restore energy supplies and people are staying outside following a warning by the seismological service that aftershocks could be expected.
The pulp mill at Lake Baikal, which had temporarily stopped work "for security reasons," resumed production, a mill spokesman said adding the mill's reserves of chlorine and other hazardous chemicals were secure.
But Alexei Nagayev said the mill "is prepared to evacuate if more quakes occur."
The research expedition delayed scheduled dives of its Mir-1 and Mir-2 minisubs for Wednesday, a Baikal Conservation Foundation official said.
"A decision has been made not to conduct dives today amid a threat of more quakes," the official said.
A member of the expedition, involved in the research to gather information on tectonic plates and a search for archeological artifacts, said earlier on Wednesday researchers and the minisubs had not been affected as the dives had been postponed due to poor weather conditions.
The minisubs are currently on a barge anchored near the lake's northwest shore in the Irkutsk region.
