People in Russia's Dagestan region have clashed with police in the latest protests against Moscow's call-up of 300,000 military reservists.
Over 100 people were arrested during protests in the regional capital Makhachkala, OVD-Info, an independent Russian human rights monitor said.
It said it was concerned by reports of the province's "very tough detentions".
Dagestan is a mainly Muslim region of Russia with a higher death toll than any other province in the war.
Recent analysis by the BBC's Russian service showed that at least 301 soldiers from Dagestan have died, 10 times more than in Moscow. The true figure is likely to be far higher.
More than 2,000 people have been arrested at mass protests since Russian President Vladimir Putin announced the partial mobilisation of military reservists on Wednesday.
While large protests have taken place in major cities across Russia in recent days - with more than 700 people being arrested on Saturday alone - the images of Dagestani demonstrators fighting with police marked a rare outbreak of violence against authorities.
Dozens of videos posted to social media showed protesters confronting police and other security officials in Makhachkala, with OVD-Info reporting that officers resorted to using stun guns and truncheons on the crowds.
In one video, a man detained by officials headbutts a police officer, before being beaten by other personnel.
Another video showed a security officer fleeing from a large group of demonstrators, some of whom attempted to grab and trip him as he ran.
Elsewhere, a large group of women confronted an officer guarding a recruiting centre and angrily condemned the war in Ukraine, with one telling the officer that "Russia is on the territory of another country".
"Why are you taking our children," the women shouted. "Who was attacked? Russia was attacked? They didn't come to us. It was us attacking Ukraine. Russia has attacked Ukraine! Stop the war!"
OVD-Info also reported that locals in the village of Endirey had blocked a federal highway, in an attempt to stop security officials seeking to enforce the draft entering the area.
Footage obtained by the group showed police officers firing automatic rifles in the air as they sought to break up the demonstration, but locals continued to block the road.
In an attempt to ease the outbreak of anger, Dagestan's Governor Sergei Melikov admitted on Sunday that "mistakes have been made" during mobilisation.
"I have already spoken about this before, but I will repeat it again: partial mobilization must take place strictly according to the criteria announced by the president," Mr Melikov wrote on Telegram.
Many young Russian men have also sought to flee the country, attempting to cross the border into neighbouring Finland and Georgia.
And there have been reports from across the country that many people ineligible for the draft have been ordered to report for duty by local recruiting officers.