The kidnaped wife of a former Salvadoran ambasssador to the United States, missing for a week from her home in a wealthy community near Miami, was rescued unharmed in Washington late last night by FBI agents after they had staked out a downtown apartment here for several days, FBI officials said.

The woman, Clelia Eleanor Quinones, 53, who was being held for $1.5 million in ransom, was rescued at 10 p.m. by an unspecified number of FBI agents who rushed her captors after she was led to a phone to call her husband, former ambassador Roberto Quinones Meza, according to the FBI.

Three men, including one who was armed, were arrested at the scene adjacent to the Pitts Hotel at 1451 Belmont St. NW, according to FBI officials. A woman suspect escaped from there, they said.

A fourth man was arrested nearby in the 1300 block of Euclid Street NW about 1:40 a.m., an FBI spokesman said. He said two other men were arrested last night in Miami and that additional arrests in the Washington area were expected.

No injuries were reported here.

"There was no violence. We had that location under surveillance, intensive surveillance, for several days," said an FBI spokesman. "But because of the danger we felt she was in, we could not effect an earlier rescue. When we had an opportunity, we jumped on it."

The agents surprised the woman's captors at a public telephone located about 12 feet from the entrance of the Pitts Hotel.

An FBI spokesman said Quinones had been kept nearby in an apartment at 2327 15th St. NW, where one of the arrested suspects lives.

About six agents were still stationed by the telephone after midnight while more than a dozen other agents were still roving around the motor hotel.

An FBI spokesman said agents believed the kidnapers, who Miami press reports said may be part of a Central American terrorist group, came directly to Washington from Miami in a van. They had described their ransom demand as a "war tax," according to the FBI.

FBI officials identified the suspects arrested in Washington as Mack Lewis Carr, 18, of 2327 15th St. NW; Robert Anthony Gerald, 19, of 4913 Illinois Ave. NW, and a 17-year-old whose name and address was withheld.

The fourth suspect was identified as Clifford Bibbs. No other information was immediately available.

In Miami, press reports said the two suspects arrested there were identified as Salvado Lacaya and a sister, Margarita.

Quinones disappeared last Friday, agents said. Her Mercedes-Benz car was found a short distance from her home in Coral Gables.

FBI officials in Miami said that news media there were aware of the woman's abduction, but had not publicized that she was missing because of death threats against her.

Quinones and her husband, who was assigned to Washington from 1977 to 1979, when the government he represented was overthrown by a military coup, were part of the wealthy landed oligarchy of El Salvador.

The couple and their families hold extensive business interests, including the concession for Coca-Cola interests, real estate, banking, a brewery, car and machinery dealerships and coffee and coconut farms, according to a close friend of the family and other Salvadoran sources.

The couple had been living in Miami because of danger stemming from the civil war in El Salvador, but traveled frequently to the country on business, according to the friend.

While in Miami, the couple has been outspoken in its criticism of communist influences in Central America and have become leaders in anticommunist activities. He has previously denounced agrarian reforms in El Salvador as failures that were "wrecking the economy."

Roberto Quinones recently became president of Salvadoran Coalition for Freedom and Independence Inc., a nonpartisan group based in Miami. His brother-in-law heads the National Private Enterprise Association, the largest business organization in El Salvador.