A court in Russia on Thursday ordered a former state TV journalist placed under house arrest for nearly two months pending an investigation and potential trial on charges of spreading false information about Russia's armed forces.

Marina Ovsyannikova was charged over a street protest last month, when she held up a banner that said, "(Russian President Vladimir) Putin is a killer, his soldiers are fascists. 352 children have been killed (in Ukraine). How many more children should die for you to stop?"

If convicted, Ovsyannikova faces up to 10 years in prison under a new law that penalizes statements against the military. The law was enacted shortly after Russian troops moved into Ukraine.

In the courtroom on Thursday, Ovsyannikova held up a poster saying "Let the murdered children come to you in your dreams at night." She first made international headlines on March 14, when she staged an on-air protest against Moscow's war in Ukraine.

"Marina became a hostage of her own conscience and a hostage of her love for her children, you see," her lawyer, Dmitry Zakhvatov, said after the hearing.

"She cannot be abroad because her children are here, and she cannot stay silent here because she's a prisoner of her conscience," Zakhvatov said. "As a mother, she can't stay silent. She sees what's going on and it's making her speak out."

In March, Ovsyannikova appeared behind the anchor of an evening Channel One news broadcast holding a poster that said "Stop the war, don't believe the propaganda, they are lying to you here." She quit her job at the channel, was charged with disparaging the Russian military and fined 30,000 rubles (US$270 at the time).

After quitting her job, Ovsyannikova became somewhat of an activist, staging antiwar pickets and speaking out publicly against the conflict.

She was fined two more times in recent weeks for disparaging the military in a critical Facebook post and with comments she made at a court where an opposition activist also accused of spreading false information about the military was remanded into custody.

According to Net Freedoms, a legal aid group focusing on free speech cases, as of Wednesday there were 79 criminal cases on charges of spreading false information about the military and up to 4,000 administrative cases on charges of disparaging the armed forces.