The military council now ruling Poland under a state of emergency flew Lech Walesa, leader of the independent trade union Solidarity, to Warsaw today for talks aimed at heading off a nationwide strike threatened by union activists.

Government spokesman Jerzy Urban denied reports that Walesa was among the 1,000 people detained after martial law was declared early this morning and told foreign reporters the union leader was "being treated with all due respect."

Urban did not say with whom Walesa met. But The Associated Press quoted informed sources as saying it might have been Stanislaw Ciosek, minister for trade union affairs, and that the session could be a prelude for a meeting with Gen. Prime Minister Wojciech Jaruzelski, now chairman of the ruling military council, Monday morning to head off the threatened general strike.

Earlier, the East German news agency ADN had carried a report from its Warsaw correspondent quoting Urban as saying Walesa had been detained. The agency later retracted the report, Reuter news agency said.

The newly formed Military Council of National Salvation issued a proclamation saying it would rule the country "until the situation becomes normalized."

The council's task, the statement said, is "to bring to naught the coup against the state, to stabilize the situation, to ensure and to execute within the framework of the law an efficient functioning of organs of administration and of economic units."

The people detained today included many leaders of Solidarity, which has challenged the Warsaw government for more than 16 months in a drive for more economic, social and political freedom.

The Soviet news agency Tass in Moscow said among those taken into "preventive isolation" were extremist members of Solidarity and illegal organizations as well as persons "responsible for causing the profound crisis." It did not give any figures.

The state-run news media reported that about 200 demonstrators at the Solidarity building in the capital were dispersed with fire hoses, AP said. It was the only reported street agitation in the otherwise apparently calm city.

The crackdown came swiftly following mounting tensions between the union and the government in recent days, but nonetheless surprised many who had watched the opposing forces step back from the brink several times in the dramatic story of Solidarity's upheaval.

The government acted after the union's national commission, during a defiant meeting yesterday in the Baltic port of Gdansk where Solidarity was born, indicated it would violate a sudden government ban on mass protest rallies. Further, the union frontally threatened the political monopoly Poland's Communist Party has held for 36 years by calling for democratic elections next year and for public referendums on several key political issues.

Polish Army troops have moved into streets and highways. Phone and most telex communications have gone dead. A curfew is in effect between 10 p.m. and 6 a.m. All trade union activity, strikes and public gatherings -- except for religious services in deference to Poland's powerful Roman Catholic Church -- have been banned.

A decree broadcast by Warsaw Radio set penalties ranging from two years in prison to death for anyone in the Army, government service or key industries who refuses to obey orders.

Poland's borders have been closed to Poles, but travel in and out of the country is said to be allowed for foreigners. The country's airspace, however, was closed today to international flights and will remain so at least through Monday.

Poland's primate, Jozef Glemp, whose church has played a critically important role in attempting to moderate throughout the crisis, appealed from Czestochowa for the country to remain calm.

The official news agency PAP reported that only the Communist Party newspaper Trybuna Ludu and the armed forces newspaper Zolnierz Wolnosci, along with "some provincial papers," would be allowed to publish.

It said military tribunals have already started functioning.

"The Ministry of Internal Affairs has instructed both citizens and institutions to hand in firearms, hunting and sports arms, flare pistols, explosives and amateur short wave transmitters," the dispatch said.

The government's action appeared to leave many Poles stunned. Along the highway between Gdansk and Warsaw today, people stood along the road curiously observing the armed columns of tanks and Army trucks.

Conversations in the restaurant Mysliwski, a roadside stop on the Gdansk-Warsaw highway, found Poles talking quizzically and uncertainly about the future.

"Will the government be able to feed us?" one person asked, thinking of the difficult winter still ahead. "A lot is still up to Walesa," said another.

In his briefing for foreign journalists, Urban said, "We have achieved peace in Poland now, in comparison to the situation of the past weeks and days. The events of last night went on without any accidents and victims. Only one dog was killed."

He reported that sit-ins were under way in no more than 10 enterprises around the country, protesting the government's action in violation of the decree against such activities. Foreign journalists have been advised not to travel outside Warsaw.

On the future status of Solidarity, Urban said the activities of the union had been suspended, but he said that does not mean the union has been declared illegal.

In Warsaw, Solidarity's regional headquarters and surrounding streets were sealed off by police and soldiers in battle dress, some armed with rifles. They patrolled downtown intersections and blocked traffic on some main streets.

A crowd fluctuating between 300 and 1,000 gathered outside the Warsaw Solidarity office, ignoring the ban on such public gatherings. As soldiers guarding the building used loudspeakers to tell them to disperse, angry union supporters jeered and some threw snowballs at Army trucks.

Those still inside the building hung out signs calling for an immediate general strike, which is the response the union's national commission approved last night in the event a Communist Party-sponsored emergency powers act passed parliament and was enforced by the government.

Leaflets appeared, also now illegal, urging Poles to maintain their solidarity in the face of a "brutal violation of public order." Workers at the Ursus tractor factory on the outskirts of Warsaw issued an appeal for a general strike as well.

News agencies reported the following:

A group of Solidarity leaders who were not detained announced that they were forming a national strike committee and said a general strike would be the appropriate reply to the government action.

"No union, no organization can allow their leaders to be repressed and the union to be deprived of its rights," according to a communique issued by the group that reached Warsaw from Gdansk tonight.

The communique, signed by one of Walesa's deputies, Miroslaw Krupinski, said the proposed general strike could be called off after all detainees were released and martial law repealed.

Informed sources said about 1,000 people had been "interned," meaning held in isolation or under house arrest without charge. Government spokesman Urban said the sweep aimed at "liquidation of anarchy," and that those detained would be released "as soon as possible." One of those seized was former Communist Party leader Edward Gierek.

In the first commentary since the imposition of martial law, the official news agency PAP called on Poles to support the military government. The commentary was distributed by Tass in Moscow.

"Martial law does not absolve Poles of responsibility. On the contrary, it weighs down as a heavy but necessary burden on everyone of us. It can last longer or shorter. Everything depends on the development of the situation, on how we all will carry our share of responsibility.

"This depends on us, our reason, on patriotism that understands supreme values and the need of sacrifices for the motherland. It also depends on whether we will be able to display the discipline that should characterize every civilized society."