SAN JUAN — Federal agents on Friday raided a public housing project believed to be one of the most violent in San Juan, serving dozens of 132 drug arrest warrants even as top leaders remained at large.

The warrants are a result of a three-year investigation into a heavily armed group that authorities say recruited minors and sold heroin, cocaine, crack, marijuana and prescription pills and killed wantonly.

Puerto Rico Police Chief Jose Figueroa Sancha said the group was involved in “multiple” killings but said he did not have the specifics. None of the suspects had been charged with homicide.

“For them, killing was something of a routine,” said San Juan Police Commissioner Hilton Cordero.

By late Friday morning, agents with the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives, as well as the Drug Enforcement Administration and Puerto Rico police, had arrested 59 suspects.

Police say 918 people have been reported killed this year on the island of four million, compared to a total of 894 last year, which was Puerto Rico's third worst year for homicides. A record 995 people were killed in 1994.

Figueroa has said that 70 percent of killings are tied to drugs and he warned that new drug traffickers would likely replace those arrested in the sprawling Villa Hermosa housing complex if residents did not cooperate with police by reporting crime.

The leaders of the group remained at large, including Victor Colon Bench, known as “El Father,” who replaced the main leader killed in 2007 and is accused of running 25 drug distribution points in the housing project under nicknames such as “Pepe Le Peu.”

The group is accused of moving 143 pounds of cocaine every year, along with 93 pounds of heroin and 79 pounds of crack, among other drugs, said assistant U.S. attorney Mariana Bauza.

U.S. Attorney Rosa Emilia Rodriguez said officials are seeking to seize $60 million in property and accused the group of intimidating hundreds of residents.

“They closed the basketball court and would not let the children play,” she said. “They took these communities hostage.”