A Russian girl dressed in pink has become a national symbol after a video of her at a protest went viral.

Tanya made throat-slitting gestures at Governor Andrei Vorobyev at a rally about toxic air pollution on Wednesday in Volokolamsk, outside Moscow.

Residents claim gases from the nearby Yadrovo landfill poisoned 183 locals, including children.

Local authorities deny the site's gas emissions are linked to complaints of poor health, according to pro-government TV.

Videos of the protests, which attracted more than 1,000 people, have been widely shared on social media with the hashtag #VolokolamskIsSuffocating.

Participants angrily threw snowballs at Governor Vorobyev, shouting: "Shame on you," and: "You poisoned our children," and struck another official in the face.

Russian opposition leader Alexei Navalny wrote admiringly on Twitter that he knew 10-year-old Tanya and that she attended all the protests in her town.

"Tanya is cool, be like Tanya," he added.

Some joked that she should replace the local governor.

In an interview with online media outlet Daily Storm, Tanya claimed the authorities were "lying all the time" and the best birthday present for her would be the closure of the landfill site.

"I just wanted to speak so people would hear my opinion and that someone would pay attention to me and close the dump. But they did not pay attention to me," she told Daily Storm.

Residents of Volokolamsk have been complaining about fumes from the landfill for months and called for it to be closed.

Parents posted pictures on Russian social media network VKontakte of children wearing masks outside the Volokolamsk hospital.

Failed presidential candidate Ksenia Sobchak posted a video of her talking to parents and hospital staff.

The protests were featured in a brief report on pro-Kremlin TV on Wednesday and a pro-government radio station blamed the landfill owners. But some people continued to complain about the lack of attention to the issue.

"All TV channels are constantly showing Syria and [Eastern] Ghouta. I guess they do not know where the Volokolamsk landfill is. Children are kept in emergency care units in Moscow regional hospitals and not a single TV presenter... says a word about it. Shame on you, corrupt journos - you are profiting off our health," Marina Sergiyenko said on VKontakte.