The meeting, planned to last two days, was intended to help opposition politicians get to know each other and collaborate ahead of parliamentary elections due in about six months. The opposition wants to remove long-time President Vladimir Putin from power.

Dozens of people, including journalists covering the event, were temporarily detained in the hotel where the meeting was taking place.

Several prominent opposition politicians and activists were among those taken into custody with prisoner transport vehicles, including Vladimir Kara-Murza. Some said they were released again after several hours.

Kara-Murza posted an image of himself in a police transport. Hours later, after he was released, he said there was a "repression machine" in Russia that had developed a life of its own.

Other detained participants posted videos of themselves at police stations. The participants said security authorities were initiating proceedings against them for cooperation with an unwanted organisation.

Police broke up the event only half an hour after it started, just as the first speakers had just taken the stage. Police forces stated later that the event involved an organisation "not wanted in Russia."

Police forces later said participants at the event were not conforming to coronavirus rules.

The Russian opposition has repeatedly spoken out about freedom of assembly violations by security forces. Attempts by dissidents to assemble and organise have repeatedly failed for this reason.

A new parliament will be elected in Russia this autumn. In the election, the United Russia party linked to President Vladimir Putin wants to defend its two-thirds majority.

Local politicians who attended the meeting were meant to coordinate to challenge the current monopoly of power of Putin's United Russia in the upcoming elections.

Jail dissident Alexei Navalny's team said it was clear why security forces broke up the opposition meeting.

"The powerful are afraid of any kind of competition during the election, that's why they are intimidating their opponents," the team wrote on Telegram.

Australian Associated Press