Protesters rally against Lake Baikal's mill operations

Around 200 people gathered in St. Petersburg, thousands of kilometres away from the lake, demanding to revoke the government's January decision to restart Baikal Paper Mill.

Another 500 rallied closer to Baikal, which holds a fifth of the world's total surface fresh water, in the city of Ulan-Ude in the Buryat Republic, according to the organisers.

The loss-making Soviet-era factory was shut in October 2008 after the government ordered it to install a system for drainage away from the lake.

Environmentalists and politicians have staged several protests in recent months, saying the waste from the plant contains harmful substances that destroy the lake's rich wildlife of 1,500 species of animals and plants.

"Putin - hands off Baikal" read a banner displayed at the St. Petersburg rally.

Prime Minister Vladimir Putin signalled in August his willingness to lift the restrictions that prevented the plant from dumping waste into the lake after diving to the bed of the lake and consulting with scientists.

"I worked myself in a paper producing industry," Grigory Borisov, a 45-year-old engineer from St. Petersburg told Reuters. "I know that Baikal is getting polluted and no purifying facility will save the lake."

Several hundred supporters of the factory, which employs 1,600 people, gathered Saturday in the city of Baikalsk, on the shoreline of the lake, which remains sacred for some Siberian tribes, in a rally organised by the mill.

A closure of the mill could lead to another ecological problem for Baikalsk, which would be left without revenues to operate water purifying plants and sewage facilities for the town, the organisers said.

The decision to reopen the Soviet-era mill is seen as part of the government's broader support for Russia's single industry towns, often in remote areas.

The government owns 49 percent of the mill. Tycoon Oleg Deripaska owns a minority stake.

(Reporting by Denis Pinchuk; Writing in Moscow by Lidia Kelly)