The four students, studying at Kostroma State University, were attacked on Friday afternoon outside a school, the source said, attributing the attack to race hate.
Two suspects have been detained and charged. One of the suspects is also being charged with an attack on an Azerbaijani schoolgirl on Thursday.
Routine attacks by skinheads and youth gangs on foreigners with non-Slavic features have been reported in several Russian cities in recent months.
In St. Petersburg, an African student was shot dead with a rifle marked with a swastika on April 7, while two Mongolian students were beaten up in the city's subway Sunday. A Chinese student was attacked outside her apartment block this month, while a nine-year-old girl of mixed Russian and African origin was hospitalized after being stabbed near her apartment building March 25.
Over the past six years, the city of Voronezh has seen at least seven apparently racially motivated killings, including the murder of a Peruvian student in October last year.
On January 11, 2006, Moscow witnessed a shocking attack on a synagogue by a 20-year-old man who stabbed nine people with a hunting knife.
These incidents have prompted Russian and foreign human-rights groups to raise concerns over the alarming spread of racist and xenophobic attitudes in the country.
