POLAND'S GOVERNMENT says that it has now closed the internment camps in which it has held thousands of people who belong to Solidarity. The tone suggests that it considers itself entitled to some credit for relaxing the "main rigors" of martial law, as Gen. Jaruzelski put it a couple of weeks ago. Before joining the applause, you will want to take note that a good many people who worked in the Solidarity movement are not publicly accounted for.

Closing the internment camps means, according to the government, that people will no longer be held without charges. But the announcement states, in the manner of a warning, that seven of Solidarity's best-known leaders, previously held in internment, have now been formally arrested and imprisoned on criminal charges. Solidarity spokesmen add that, beyond these prominent seven, there are several thousand people currently being held in prison on charges of violating the prohibitions of martial law. There are further reports that some hundreds of Solidarity's active members have been drafted into penal battalions, the existence of which the government does not acknowledge.

As for Solidarity itself, it exists underground now -- but it exists. If the proliferation of underground journalism were not evidence enough, there is the uneasy deportment of the Jaruzelski government. It suggests that the people in the best position to know are well aware of the strength of the opposition to them.

After a year of martial law, the government wishes to present the aspect of a country returning to normality and stability. The effort is unconvincing. The security operation is sufficiently well organized now that the government is prepared to allow some of its adversaries, including Lech Walesa, a measure of highly conditional freedom. But it continues to be clear that the authority of Gen. Jaruzelski's government rests essentially on the riot police and their ability to prevent any public gathering of which the general disapproves.