Migrant workers are committing fewer crimes in Moscow, but those they do commit are getting more serious, the city's chief prosecutor said Friday.

"Last year, 26 percent fewer crimes were committed by migrants in Moscow, but their cruelty and severity has intensified," Sergei Kudeneyev said at a meeting of the City Prosecutor's Office, Interfax reported.

Gastarbeiters were responsible for more murders, attempted murders, severe beatings, robberies and rapes last year than the year before, Kudeneyev said.

He asked officials to "take additional measures to put an end to the crimes committed by migrants."

Speaking about illegal immigration, Kudeneyev noted that last year there were 2,000 violations of migration laws, double the amount in 2010.

"A portion of labor migrants usually are not registered in the prescribed manner, which adversely affects the state of crime in the city," he said.

There are currently 1.84 million foreign migrants living in Moscow, he said. That is about 15 percent of the city's total population.