Eastern District police swooped down yesterday afternoon on alleged street drug dealers and users as they executed their third "Operation Clean Sweep" in two years.

In the operation, which is expected to last through the weekend, uniformed patrols and plainclothes officers are moving systematically through at least 40 predetermined areas where heavy drug trafficking has been reported.

In the first six hours, officers arrested 15 people on several drug charges and confiscated more than $300 in cash and small quantities of cocaine.

In the two previous operations, about 50 people were arrested each time.

"Although 'Operation Clean Sweep' took many hours of investment, it would not be possible without the involvement of the citizens who alerted us to the problem," city police spokeswoman Agent Arlene K. Jenkins said.

For the past few months, city police have been collecting information about drug activity from residents throughout the district. Officers then mapped locations to include in the sweep with the assistance of the district attorney's office.

Twenty officers directed from a command post in the district's narcotics division are involved.

One of the first suspects arrested was an 11-year-old boy, who was picked up in East Baltimore with five vials of cocaine and about $160 in cash hidden in the waistband of his sweat pants. The juvenile was subsequently released to his mother.

Sgt. John Sieracki, who heads the Eastern District's narcotics investigations, said the operation is proceeding smoothly.

"We're trying to make an impact, trying to let them know that we're out there," said Sergeant Sieracki. "The public is doing more than their fair share. They are calling us with information about drug activity, and they are writing us. The only thing they haven't done is lock the offenders up.

L "We're doing our best to reduce the activity on the street."