Six fugitives sought in connection with a Northern Virginia drug smuggling ring were arrested yesterday in Costa Rica, Alexandria federal prosecutors said.

The six, along with 14 other persons including two Washington area attorneys, were indicted last month by a federal grand jury in Alexandria on 38 counts of racketeering, drug and conspiracy charges in connection with a marijuana and hashish-smuggling organization headquartered in Northern Virginia.

Drug enforcement agents working in cooperation with the U. S. State Department made yesterday's arrests in San Jose, Costa Rica. All six suspects had been living in the Central American country since fleeing the United States late last year, according to the prosecutors. They are in custody of Costa Rican authorities pending extradition.

The six were identified as Barry W. Toombs, Julian T. Pernell, Sidney L. Pernell Jr., Carl D. Pernell, Kevin B. Munley and Stuart D. Ebner.

According to the indictment, the smuggling operation began in 1975, when Toombs and Julian Pernell allegedly met with an unindicted coconspirator and purchased a $40,000, 41-foot boat named the "Banana Quit," that was used to transport 5,000 pounds of marijuana into Marathon Key, Fla., from Central America. The drug was then taken to the Tysons Corner area of Fairfax County, the indictment says.