ST. JOHNS COUNTY, Fla. -- The St. Johns County Sheriff's Office arrested 34 people Friday morning in connection with illegal narcotics transactions.

Police said they targeted 55 individuals, and 21 of them are still being sought.

The sheriff's office said its special investigations unit concluded a two-phase operation titled "Operation-Street Sweeper" that stemmed from numerous complaints in reference to drug activity occurring within the county.

Officers said they targeted the most active street-level cocaine base distributors, prescription medication distributors and marijuana distributors.

"Guys who sell drugs are smart, and they figure out what we do," St. Johns County Sheriff David Shoar said. "They watch our practices, so we've had to evolve a little bit with some unique was to do it."

Police said the illegal narcotics transactions occurred as far north as Ponte Vedra and as far south as Hastings and encompassed the entire county.

Police said the first phase of the operation ran from July 1 through Sept. 10 and consisted of confidential informants as well as undercover officers from the St. Johns, Flagler and Putnam County Sheriff's offices.

Officers said the undercover narcotics transactions occurred between the them and informants and known narcotics distributors. They said the majority of those distributors targeted were known drug offenders with previous drug convictions.

Police said arrest warrants were obtained for those individuals after the first phase of their operation was completed.

Investigators said the second phase of the operation took place Friday when members of the St. Johns County Sheriff's Office, including members of the COPS unit, warrants unit and detectives were assigned to seven arrest teams.

They said each team was provided information on five to six individuals to be apprehended.