U.S. federal drug agents swept through Puerto Rico's main airport Wednesday and arrested more than 30 people suspected of smuggling millions of dollars of cocaine into the United States aboard commercial passenger airline flights.

Three other people were arrested at the Miami and Dallas airports. Suspects include baggage handlers and employees with American Airlines, which helped drug enforcement agents with their investigation.

Authorities believe the cocaine was smuggled from South America into the Luis Munoz Marin airport in San Juan and passed over to gang members in the airport who had already cleared security.

The drugs were then flown to such large American cities as New York and Boston. Officials say the drug ring had been active for 13 years.

Puerto Rico is a major transfer point for drug traffickers operating between South America and the United States.