The State Department yesterday announced that organized intimidation and violence, a flawed campaign and voting irregularities tainted last Sunday's elections in Romania, unfairly favoring the ruling National Salvation Front and President Ion Iliescu, who won in a landslide.

The tone of yesterday's critical statement contrasted sharply with earlier evaluations this week by a White House delegation that called the balloting "free" and "enthusiastic." But the State Department did not call the elections invalid, saying only that the Front will have to "establish its democratic credentials."

"The United States has concluded that serious distortions and irregularities marked the Romanian electoral process, which unfairly favored the national Salvation Front to the disadvantage of its competitors," spokesman Margaret Tutwiler said. "These included organized acts of intimidation and violence directed primarily against opposition candidates and their sympathizers."

She also expressed official concern that secret police activity may have compromised the vote in Romania's first free election in more than half a century. Asked why the administration had not spoken out earlier, another official said it had waited to "digest" observers' reports.

The National Salvation Front is dominated by longtime communist officials once close to former Romanian dictator Nicolae Ceausescu and assumed power during the December revolt that led to his execution. The revolt ended Ceausescu's 25-year reign and more than four decades of rigid Communist Party rule.

"We lack substantiating evidence that these voting-day irregularities were of sufficient weight to have altered the outcome," Tutwiler said. The United States would not recommend another election if it was not satisfied with further steps towards democratization, she added.

Keith Schuette, president of the National Republican Institute for International Affairs, said the main problem lay with constraints preceding the campaign and Romania's legacy of oppression rather than the balloting itself.

Schuette was one of 60 observers from 19 nations who included representatives from the National Democratic Institute for International Affairs.

"I feel this was the most unfair campaign I have ever witnessed," he said. "The people of Romania were not encouraged to understand there were alternatives to the National Salvation Front in a country that only five months ago overthrew a dictator. . . People came out and reverted to type. They voted for the people in power at the time and did what they have done for the past fifty years."

Meg Thompson, Schuette's program director, cited complaints by opposition groups of inadequate media access, physical and verbal intimidation. She said the most vivid example was a gang that swung clubs to break up a rally for a presidential contender.

Thompson said ballots pre-marked for the National Salvation Front were also discovered and Peasant Party workers were "beaten up and run out of certain towns." She confirmed the administration's conclusion that the reported irregularities -- such as the presence of local officials inside voting booths -- "did not change the actual outcome."

She added, "We did not observe any centralized fraud as we did in Panama last year or during the last election of {President Ferdinand} Marcos in the Philippines."

Thompson criticized the present government for failing to identify or bring to trial members of the hated Securitate secret police who fired on demonstrators during the rebellion.

"There is a great deal of suspicion among the electorate. Many feel the Securitate has not been dislodged and questions persist about where its members are, what they are doing, what their relationship is to this regime," she said.