New York (CNN) -- More than 250 illegal guns have been seized by the New York City Police Department in the largest gun bust in the city's history, Mayor Michael Bloomberg announced Monday.
The guns were smuggled into New York City from North Carolina and South Carolina between September 2012 and July 2013 through two separate trafficking operations, according to a news release from the city's special narcotics prosecutor.
Walter Walker, 29, of Sanford, North Carolina, and Earl Campbell, 24, of Rock Hill, South Carolina, are accused of hiding the firearms in luggage carried on buses that offer cheap fares and operate near Manhattan's Chinatown neighborhood, authorities said. They sometimes transported as many as 14 firearms at a time, and the guns were usually sold within hours of arriving in the city, authorities said. It is not clear which bus companies they used to travel to and from New York.
An undercover police officer met with Walker and Campbell separately more than 45 times and bought 254 guns, whose sales totaled nearly $160,000. Wiretaps of cell phone conversations and text messages revealed co-conspirators who assisted them in obtaining the weapons for sale, authorities said in a statement.
"Year after year, guns flow into our city from states that don't have commonsense gun laws that keep guns out of the hands of criminals. North and South Carolina, for instance, still have weak laws that allow criminals and traffickers to easily buy guns," Bloomberg said.
The 254 guns sold included high-capacity assault weapons, a fully automatic machine gun, and guns that are commonly used in violent crimes. Those included pistols and guns that can hold magazines with 30 or more rounds, according to Bloomberg.
Walker and Campbell are among 19 people arrested in association with the case. All face numerous counts of conspiracy, criminal sale of a firearm, criminal possession of a weapon and other crimes. It was not clear who their defense attorneys were as of Monday evening.
Walter and Campbell worked separately but used similar methods in their operations. Both employed a network of individuals in their respective hometowns who had access to black market guns and who were aware that the guns would be illegally resold in New York City. They also recruited associates in New York, who assisted them in conducting sales. The weapons sold fetched at least three times their original price, according to the police department.
Bloomberg said Monday that the percentage of guns used in crimes that are brought in from out of state had increased from 85 to 90%. Two of the top sources for gun crimes in New York are North and South Carolina, he said.
"It is impossible to know exactly how many victims might have suffered had officers not identified and investigated these gun traffickers," said Police Commissioner Ray Kelly. "But thanks to the undercover officer in this case and the efforts of the NYPD Firearms Investigations Unit and prosecutors, instead of being used in crimes these guns are now out of commission."
Of the 19 people charged, seven have been arraigned in Manhattan Superior Court. Another nine are currently in custody in North Carolina. Three were already in prison on unrelated charges.
New York authorities worked with police departments in Sanford, North Carolina, and Rock Hill, South Carolina.