Federal agents in the Roanoke area have made nine arrests and confiscated nearly 700 pounds of Bolivian cocaine said to be worth millions of dollars in what was described as the largest cocaine seizure ever in the mid-Atlantic region.

The authorities said yesterday the seizure was part of an undercover project set up last year to stop the flow of drugs to areas outside of a federal task force's blockade in Miami. The federal Drug Enforcement Administration, FBI, IRS and Virginia State Police participated in the case.

"The coke smugglers are forced to go to great extremes to avoid the blockage in south Florida. They're having to reach far north and far west to locations they think will be safe for their smuggling," DEA spokesman Robert J. O'Leary said last night.

The cache included $1.3 million and a twin engine aircraft, authorities said. Another 1,040 pounds of the drug destined for Roanoke were seized earlier in two raids, one by the U.S. Coast Guard in the Gulf of Mexico and another by the Colombian army in Colombia, officials said. The largest reported seizure of cocaine in the U.S. was 3,906 pounds, nabbed in Miami in 1982.

As part of the plan, undercover agents posing as smugglers agreed with several suspected Florida smugglers in December to bring the drug into the country, according to a statement released yesterday by DEA. On Thursday, the 700 pounds of cocaine was brought into Roanoke from Panama by the undercover agents and was taken to a secret location in the state.

On Saturday, two South Americans, one of them the son-in-law of a man considered to be the biggest cocaine trafficker in Bolivia, were arrested after arriving in Roanoke from Panama in a plane supplied by undercover agents.

Seven alleged drug dealers who live in the United States were arrested yesterday as they arrived at an undisclosed location to pick up the cocaine, according to officials who said the drug was bound for distribution in New York and Miami. All nine have been charged with conspiracy to import and distribute cocaine.

Six of those arrested are Florida residents, one a New York resident, and two are from South America.