After days of misleading statements, Russian authorities acknowledged today that they have detained Radio Liberty correspondent Andrei Babitsky, who has angered the military with his reports from the rebel side of the war in the separatist region of Chechnya.

The arrest five days ago is another example of how the Kremlin and the military are stepping up the pressure on journalists, using a variety of tactics to clamp down on any critical reporting of the war against Chechen separatists.

Babitsky's arrest came as the Kremlin rehired its former press spokesman, Sergei Yastrzhembsky, and put him in charge of a renewed information campaign. Gen. Valery Manilov, deputy chief of the general staff who repeatedly has denounced Western and Russian reporting on the war, is serving as the military spokesman for the new effort.

The Interior Ministry announced tonight that Babitsky, who disappeared in the Chechen capital of Grozny about Jan. 15, was arrested Jan. 23 at the Staraya Sunzha checkpoint as he was leaving the city. The Interfax news agency quoted spokesman Oleg Aksyonov as saying Babitsky was detained because he did not have an accreditation card issued by the military and, according to the Reuters news agency, "because of information he allegedly spent time with illegal groups."

Aksyonov told Reuters that "after some necessary formalities he may be released. . . . I think he will most likely be released."

The Russian forces have detained correspondents on grounds that they lack accreditation, but have usually released them quickly. The military has severely limited access to the combat zone, granting it under heavily controlled circumstances to the few correspondents it is willing to accredit.

Many journalists, including Babitsky, have tried to cover the war without accreditation, which is difficult and risky.

It is highly unusual for the Russian forces to hold a correspondent for five days. Both Yastrzhembsky and Manilov have made misleading statements about Babitsky's whereabouts to reporters. On Jan. 26--three days after he was arrested--Yastrzhembsky said in response to a question about whether Babitsky was detained by the Russian forces: "Detained by the federal forces? I do not know about that. What I do know is that Mr. Babitsky had left Grozny and vanished."

Yastrzhembsky said Babitsky was not accredited, and "for this reason his security was not guaranteed, and, as you see, it was not ensured."

This morning, five days after Babitsky was taken into custody, Manilov said, "I don't have any information about him now. I don't have information confirming that our bodies are holding him." He promised that "as soon as we find him, we will help him actively in every way we can."

Babitsky, 35, brought back unprecedented video interviews and tape of the Chechen fighters that was broadcast in late December by the commercial NTV television channel.

CAPTION: Radio reporter Andrei Babitsky was arrested by the government five days ago as he was leaving Grozny.