Members of a U.S. congressional delegation to the Madrid conference on detente sharply criticized Soviet intervention in Afghanistan today and declared that the Reagan administration will maintain the U.S. commitment to human rights.

The tough remarks directed at Moscow were part of a concerted drive launched by Western allies at the conference to focus attention on Afghanistan despite Soviet attempts to keep its actions there out of the spotlight.

Rep. Dante Fascell (D-Fla.) told a key conference committee: "The situation is one of bloody, brutal repression instigated and perpetuated by the Soviet Union, depriving Afghanistan and its people of their independence and freedom."

Fascell, who joined the U.S. delegation at the conference this week at the head of a five-member congressional delegation, was forced to hold back his speech for 24 hours as the Soviet Union raised procedural objections in an attempt to stave off the criticism of its invasion of Afghanistan.

As the objections were turned aside, Fascell was joined by speakers from other NATO countries, among them Britain, West Germany and the Netherlands, in a move to shift the emphasis of the European security conference onto the human rights principles violated by Moscow with its intervention nearly a year ago.

The succession of tough protests ignored repeated Soviet arguments that the intervention in Afghanistan was covered by friendship agreements between the two nations and that it lay outside the scope of the debate on East-West detente in Europe.

A Soviet delegation spokesman said Fascell's speech and those of other Western representatives were "a repetition of old stories" and accused the NATO group of refusing to face the "essential problems of the European continent, which are political and military detente and disarmament."

The barrage over Afghanistan came as the Madrid meeting -- the Conference on Security and Cooperation in Europe, grouping 33 European states, the United States and Canada -- moved into its third formal week with delegates splitting up into committees to review the progress of detente.

The Afghan issue was raised at the key closed-door meeting scheduled to debate violations of the detente principles that were enshrined in the Final Act of the Helsinki Conference in 1975.

Fascell accused the Soviet Union in detail of violating six of the 10 Final Act principles and said: "Efforts to defend the Soviet invasion are as hollow and unconvincing today as they ever were."

Earlier Fascell and Sen. Claiborne Pell (D-R.I.) told a press conference that the new administration would remain committed to the human rights issues that have been forcefully expressed so far as the Madrid conference.

"The nuances might vary from time to time but there will not be a fundamental change," Fascell said.

Rep. Benjamin Gilman (R-N.Y.), who was also on the panel at the press conference, stressed that human rights is a bipartisan issue with people "very strongly committed on both sides of the aisle."