Viido Polikarpus, a demonstrator against the Soviet Union's occupation of the Baltic Sea states, was arrested Saturday on a charge of crossing a police line, and not for making threats against the president, as was reported in an article Sunday.

Marking the 45th anniversary of the Soviet Union's occupation of the Baltic Sea states, about 100 persons staged a rally yesterday in Farragut Square and a march to the nearby Soviet Embassy, where three of the demonstators were arrested.

Dressed in black and white striped baseball shirts and linked by chains, 45 of the Latvian, Estonian and Lithuanian Americans marched from the rally to the embassy on 16th Street.

Three men approached the embassy, and after being warned by Secret Service officers to move on or risk arrest, they rattled the gates in an effort to present a list of demands to the Soviet ambassador.

Aristids Lambergs, president of the American Latvian Association in the United States, was arrested along with John Grigsby and Janis Cerbulis and charged with congregating within 500 feet of an embassy and refusing to leave the premises.

Jack Taylor, a Secret Service spokesman, said all three men would be released yesterday on $50 bond.

He said a fourth man, Daniel Nolan, was arrested about the same time for verbal threats against the president, and another man, Viido Polikarpus, also was reported arrested in the incident.

Authorities transported Cerbulis, 71, to Georgetown University Hospital for what doctors said might have been a heart attack suffered during his arrest.

American Latvian Association spokesman Ojars Kalnins, who was one of the leaders of the rally, said Cerbulis told him from his hospital bed that had he died at the embassy gates, "It would have been a necessary sacrifice."

Kalnins said, "They're no different from the people protesting at the South African Embassy. They're fighting for human decency."

The Soviet Union, with no opposition from its World War II allies, occupied Estonia, Latvia and Lithuania -- three countries with distinct cultures and languages -- in 1940 and transformed them into Soviet Socialist Republics.

Kalnins said that between 1940 and 1949 the Soviets deported, detained in concentration camps or killed 600,000 citizens of the three countries.

"The minimal [goal of the coalition] is at least to get pressure on the Soviets to free political prisoners," he said