Rep. George V. Hansen (R-Idaho) visited hostages at the U.S. Embassy here today and said he found them in "relatively comfortable circumstances," although their hands were still bound, but "anxious" to be released.

Hansen, who said he is here on a private mercy mission, was the first American allowed into the embassy compound since it was seized Nov. 4 by militant Iranian students.

He said he was able to see "fewer than 20" of the 49 hostages still being held, but considered his visit important for the morale of those captives and as a likely first step toward further contacts with them.

Hansen, who spoke at length with the militant students and later appeared on Iranian television, said he thought he had achieved a "significant breakthrough" with Iran on his proposal for U.S. congressional hearings on deposed Shah Mohammad Reza Pahlavi's alleged misdeeds.

Hansen's dramatic visit to the American hostages came on a day of confusing announcements about a planned trip by Iranian Acting Foreign Minister Abol Hassan Bani-Sadr to the United Nations, where the Security Council has been asked by Pakistan to look into the Iranian-American crisis.

The official Pars News Agency announced that Bani-Sadr would go to New York Monday to present Iran's case before the Security Council, but four hours later a Foreign Ministry spokesman said the trip would not take place for at least a week. He cited a Dec. 2 referendum on a new Iranian constitution and the coming Moslem holy day of Ashura as reasons.

Hansen, whose visit needed approval from Bani-Sadr; Ayatollah Ruhollah Khomeini, the country's religious leader; and the ruling Revolutionary Council, said the hostages had been given no advance notice that he was coming.

When the burly, 6-foot-6-inch congressman appeared before the first of the hostages, he said, "The guy looked up from his book and couldn't believe it. It was something, to see the light in their eyes when they saw somebody from home. That's something I'll never forget."

"There was a happy group of people and it brings tears to your eyes when those people saw one of their country-men walk in and grab them by the hands and say, 'How are you?' and 'Glad to see you.'"

"If that doesn't make every dime, every sacrifice worthwhile," said Hansen, who had paid his own way to Iran, "then I don't know what would."

The hostages, he said, seemed "not quite as tanned and healthy-looking" as if they had been outdoors, and "some of them had a little bit of what you'd call cabin fever."

"They could stand a change of clothes and a good bath," he said. "You don't like to see people treated like that." Several hostages, he said, told him they would "sure like to get a change of clothes."

"Some guys probably have been sitting in one set of clothes too long," he added, "and probably need to wash their hair. You know, after their hair gets so dry and so caked it flecks a little."

Hansen said he had seen no "visible signs of abuse" of the hostages he visited.

Among those he saw were the last remaining black hostage, Charles Jones, and Los Angeles businessman Larry Rosson, who was in the embassy at the time of the attack. He said he did not see the two remaining women, political officer Elizabeth Ann Swift and Katherine Koob, an official of the Iran-America Society.

Thirteen hostages -- eight black men and five white women -- were released a week ago.

Hansen reported that all the captives he saw had their hands tied with loose bonds that allowed them to read books. Some were barefoot, he said. When he asked one hostage if he managed to keep warm, Hansen said, he was told, "Yes, when we wrap in blankets."

One of the hostages he saw was getting over a case of chicken pox, he said, and another had a cold.

Hansen said he did not tell the hostages about the events of the past three weeks or about developments in the U.S.-Iranian crisis in order not to increase their worries.

He said the foreign minister, Revolutionary Council and students all said his proposal for congressional hearings was a "good initiative" even if it fell short of Iran's formal demand for the shah's immediate extradition to face trial here.

"I tried to tell them that you've got to sit through a congressional hearing sometime and watch someone get dissected with a scalpel read good over a period of weeks and months to appreciate that's a pretty effective forum," he said, "and it will get to the bottom of things."

He thus sought to convince Iranians often ignorant of congressional powers and doubtful that any American government body would conduct a meaningful investigation of alleged misdeeds involving the shah and his long relationship with various U.S. administrations.

Hansen's carefully balanced approach of blaming both Iran and the United States for errors in judgment and provocative actions apparently pleased his hosts.

Speaking at a news conference after the visit, Hansen said he had "nothing but praise for some" Iranian officials. He described them as "very gracious, responsive, responsible people" and said their authorization of his visit was "a tremendous accommodation."

Hansen insisted that he had made no "questionable concessions" as a price for visiting the hostages, although student leaders had said he would be required to condemn the shah first.

"I can assure you it was all done in a way I think my country can be proud of," he said.

Meanwhile, the Kurdistan Democratic Party today ordered a 20-day cease-fire effective at noon throughout western Kurdistan Province, which has been demanding autonomy. The party demanded that all government Revolutionary Guards who are not Kurds be withdrawn from the province.

Left unclear was whether several smaller Kurdish groups would honor the cease-fire.

As many as 10,000 highly disciplined Marxist-Leninist Fedaye Khalq guerrillas and their sympathizers staged a show of force in Tehran, braving Islamic student opposition and marching on the U.S. Embassy today.

Although the extreme left made a timid showing last week, this was the first time since they went underground in the summer that they had been seen in such large numbers in public.

They were followed every foot of the more than mile-long march between Tehran University and the embassy by Islamic stalwarts shouting "Fedaye are American agents," and "God is great."