More than 2,000 troops and security agents are patrolling the Jiu Valley region of western Romania in the wake of the country's biggest postwar strike, involving some 35,000 miners.

During the first visit by Western journalists to the valley since the disturbance at the beginning of August, miners this week described how they had forced President Nicolae Ceausescu to break off a holiday by taking sescu two of his senior aides hostage. The strikers went back to work only after lengthy negotiations in which Ceausescu personally indicated that most of their demands would be met.

Fragmentary details of the three-day strike have been reaching the outside world over the last month. Reports of social unrest are rare in Romania which, despite its staunchly independent foreign policy is considered one of the most repressive of Communist societies internally.

Although authorities temporarily regained control in the valley by making some concessions. Western diplomats believe that the strike was a severe embarassment for Ceausescu. Coming just a few days before a visit to the Soviet Union, it raised questions in the Kremlin over his ability to keep order in his own house and about his policy of investment in heavy industry at the expense of consumer goods.

The initial reaction of Romanian officials to Western reports of the strike was to deny that it ever took place. Now they refuse to comment. The following account is based on conversations with miners and their families who took part in the demonstrations. In order to protect informants, names are not mentioned.

The focal point of the strike was Lupeni, a mining community of some 35,000 inhabitants nestled in the beautiful western Jiu Valley. The town is a mixture of modern high-rise apartments and single-story terraced row houses. At the center of the town is the mine, covered with soot and grime but emblazoned with red banners reading "long live the Communist party of Romania."

On Aug. 1 miners working underground refused to return to the surface unless a list of demands was met. Their grievances included poor working conditions, inadequate food supplies and inefficient management. The spark which led to th estrike, however, was a new pension law passed by the National Assembly in June that required miners to work longer for a smaller pension.

On Aug. 2, the strike spread to the entire Jiu Valley - a region dotted by mines employing 40,000 surface workers and 5,500 miners underground. Ciausescu sent Deputy Prime Minister Ilie Verdet, Labor Minister Gheorghe Pana, and Mining Minister Constantin Babalau to talk to the strikers.

"In all my life, I have never seen such a scene," one demonstrator said. "The crowd stretched as far as the eye can see. When the ministers arrived, they were seized by the leaders. We took the food that we have to eat and threw it in their faces, saying, 'you eat that food'".

Holding two of the ministers hostage, the miners demanded to meet with Ceausescu. The president arrived by helicopter the next day. Accustomed to mass adulation, he was confronted instead by a crowd of angry miners who at first prevented him from speaking with jeers and shouts.

When the miners, allowed Ceausescill to speak, he adopted a cociliatory tone criticizing local party officials and mine managers. He promised the strikers that the pension law would be revised and that pay and working conditions would be improved.

Truckloads of food were rushed to the area - high quality meat, butter, and other goods usually difficult to get. Party organizers told the miners they had won their demands and the strike was called off.

Three months later, the Jiu Valley miners are preparing for a tough winter. The Euphoria which followed an apparent victory has given way to cynicism and fear.

"For a short time, life improved," one miner said. "The shops were full of food and new pension scheme was announced which appeared to benefit us. But now the shops are empty again, and we're being made to pay for the strike."

The miners argue that their pay increases exist on paper "In August our salaries were cut 40 per cent because we failed to meet planned targets. And even under normal conditions, production is usually 5 to 25 per cent under plan - so we never get what's announced."

Reports circulating in Bucharest that large numbers of miners have been removed from the valley and sent elsewhere in Romania could not be confirmed in Lupeni, but the miners said that the strike leader was taken away by security police in the night with his wife and children.

President Ceausescu appears confident that order has been restored in the Jiu Valley, since he visited there Nov. 9 and 10. Accompanied by his wife Elena, and dressed in miners costume and mask, he was awarded the title of "honorary miner of the Jiu Valley." The official Communist Party newspaper Scintela said grateful miners in Lupeni expressed the hope that Ceausescu - expressed the hope that Ceausescu - would "live for many years - for the welfare of the people and for the country."

"What a charade," said one miner when asked about the ceremony.

There is a long tradition of working class dissent in the Jiu Valley going back to 1974. One miner said his father took part in a big 1929 strike at the Lupeni mine for workers' freedom against the capitalist bosses. "Am I free now?" he asked, and by the way of reply crossed his wrists.

It is difficult to say what effect events in the Jiu Valley will have on the rest of the country. Although the strike was never mentioned in the official press, word travels fast and most Romanians have a good idea about what happened.

While it seems unlikely that other Romanian workers will copy the miners, Western diplomats believe that the strike could be an initial symptom of the strains of forced industrialization. Ceausescu's stated goal is to transform Romania into a modern industrial state by the end of the century, whatever the sacrifice.

There have already been reports of unrest - but no serious trouble - among railroad employees and workers at a major metallurgical factory in Bucharest.

President Ceausescu's own position does not appear to have been adversely affected by the strike. "Once again he has shown that he is a master politician capable of defusing potentially explosive situations," one diplomat said. He handled it very nimbly. He backed off where he had to, but otherwise clamped down."

Other heads, however, have rolled. Some party leaders in the Jiu Valley region have been dismissed as well as a trio of deputy ministers at the Ministry of Oil Mines.