Boston police say they are cracking down on drug trafficking, violent crime and gang activity in the city.

A spokesman for the Suffolk district attorney's office says about 30 people were arrested on various charges in the raids in the city's Roxbury neighborhood that began at about 6 a.m. Tuesday. Many of the defendants face cocaine and heroin trafficking charges.

Warrants were out of district court, Superior Court and federal court.

A police department spokeswoman says suspects include gang members and authorities are obtaining search warrants for several houses in the neighborhood.

More details are expected to be released later Tuesday.