WASHINGTON (NEXSTAR) — The U.S. Department of Justice says federal law enforcement officers made 1,500 arrests in June as part of a crackdown on the most violent offenders dubbed Operation North Star.

The Biden administration has been facing mounting pressure to address a spoke in violent crime in major cities around the country. Operation North Star, which is run out of 10 such cities, focused on criminals wanted for the most serious offenses, like murder.

“We are incredibly grateful for the efforts (of the U.S. Marshals) to take the most dangerous shooters off the street,” U.S. Attorney General Merrick Garland said at a press conference Wednesday. “I know how hard and dangerous this work is.”

Among the arrested were three people suspected in a June 4 shooting on South Street in Philadelphia that killed three and injured several others.

This as the nation mourns the death of seven people in a mass shooting at a Fourth of July parade in the Chicago suburb of Highland Park, Illinois.

“This location is just 20 minutes from the house I grew up in,” Garland said of the Highland Park shooting, calling it “just another horrific reminder of the violence and really the gun violence that we face and that we must do everything in our power to end.”

President Joe Biden and Vice President Kamala Harris have renewed their calls to ban assault weapons, citing the Highland Park shooter’s use of a high-powered AR-style rifle. Lake County, Illinois, State’s Attorney Eric Rinehart echoed that call.

“There was a ban of these types of weapons between 1994 and 2004,” he said Wednesday. “Everything shows that these types of horrifying, devastating incidents went down during that time.”

There is still no appetite among congressional Republicans to ban assault weapons. Senate Republican leaders say the latest gun safety package tackles what Republicans have blamed as the root of the problem: mental health.