Officials in the southern Russian city of Pugachev are struggling to contain an outpouring of anti-migrant anger after a Chechen teenager allegedly stabbed to death a local paratrooper during a brawl in a cafe last Saturday.
Investigators say the 16-year-old Chechen and 20-year-old Ruslan Morzhanov, half-Russian and half-Tatar, began drunkenly fighting over a girl before the Chechen stabbed Morzhanov.
He died hours later, after which police detained the suspect.
Although local officials have attempted to play down speculation the killing was motivated by ethnic friction, residents took to the streets to call for the expulsion of all unregistered and unemployed Chechens in the city of 40,000 located in the Saratov region.
Angry mobs rallied outside a local administration building, temporarily blocked a major highway and stormed a local Chechen community, provoking a mass brawl.
The public fury prompted a visit on Tuesday by the regional governor, Valery Radayev, who promised a swift investigation, the Russian news agency Interfax reported. The city authorities have also asked local businesses to stop selling alcohol until the situation stabilizes.
The episode highlights the country's uneasy ethnic balance between Russians and those from the predominantly Muslim North Caucasus region, which includes Chechnya.
Rampant employment in that area has forced the mass migration of residents to other major cities and regions in Russia. Although they are Russian citizens, they are often viewed as outsiders and vilified by a burgeoning nationalist movement for allegedly snatching up jobs from ethnic Russians.
Those sentiments have resulted in mass protests, such as the annual Russian March, a rally held in Moscow that typically attracts thousands of angry Russians denouncing migrants from the Caucasus and former Soviet Central Asia.
Mass brawls between groups of Russians and people from the North Caucasus are also frequent, especially in Moscow and other large cities.
Chechens have come under particular criticism for their association by many Russians with the two brutal wars waged between rebels and government forces in the 1990s and early 2000s.
When an anti-Chechen riot prompted by a provincial barroom murder last made headlines in 2006, President Vladimir Putin responded by saying the government had a duty to protect the "native population" from criminal groups "with an ethnic flavor," before the government restored Soviet-era quotas on foreigners working in shops and markets.
A recent poll by the respected Levada Center found that about half of all Russians wouldn't mind seeing Chechnya break away from Russia.