Soviet dissidents today accused police of breaking into the office of an unofficial journal and arresting editor Sergei Grigoryants without arrest or search warrants. They demanded his immediate release. Grigoryants' wife, Tamara, told a news conference in Moscow police still were guarding the small country house outside the city where Grigoryants was arrested Monday. Andrei Babitsky, an editor of Grigoryants' Glasnost magazine, said almost 400 copies of the journal and a new publication for young people had been taken from the house. Grigoryants, a former political prisoner, had agreed to allow a group seeking to found a political party called the Democratic Union to challenge the Communist Party to hold its final organizing session at his editorial office Monday afternoon. `He is not a member of the group,'' Mrs. Grigoryants said of her husband. ``He intended to be there as an observer, nothing more.'' The house is in the village of Kratkovo, about 25 miles southeast of Moscow, in an area closed to foreigners. Correspondents could not travel there to get first-hand information. After the arrest of Grigoryants and several others, about 70 people gathered at a nearby club to form the political party, which calls for multi-party parliamentary democracy, independent trade unions, a new constitution and withdrawal of Soviet troops from Eastern Europe and areas of the Soviet Union seized in World War II. During the weekend, 60 of the group's supporters were reported arrested in Moscow and one of its founders, Yuri Mityunov, said Monday that 14 remained in jail. Communist Party chief Mikhail S. Gorbachev has called for more democratic election procedures, including multiple-candidate elections. Grigoryants' magazine is named for Gorbachev's policy of glasnost _ openness on some social issues. Lawyer Valentin Yelisyenko said police had no arrest warrant for Grigoryants or any of the others, and no search warrant to enter the building. He said he was allowed to talk to Grigoryants at the local police station about five hours after the arrest, and even then police had no documents that would have permitted them to make the arrest. The Independent Union of Journalists of the USSR, a group publishers of unofficial journalist which Grigoryants heads, issued a statement saying, ``the repressive measures against the chief editor of the journal Glasnost we regard as one of the main signals that governing organs of the country are undermining those hopes they sowed in the spirits of the people.'' It demanded that Grigoryants be freed at once, that impounded copies of Glasnost be returned, court action be started against police who arrested Grigoryants. The statement also said that if there is a legal basis for action against Grigoryants, the reason should be stated publicly. Babitsky said police first arrested Grigoryants outside the house. Twenty minutes later they returned, broke down five doors and arrested four other people, he said. He said Grigoryants did not resist. Grigoryants later was found guilty of disobeying a police officer and given a seven-day jail sentence, but Yeliseyenko told reporters that dissidents had not been able to determine the charges against the other men. Dissidents said they were told police acted on a complaint by the daughter of a 96-year-old woman who rented the country house to Grigoryants that he had no right to be there. Mrs. Grigoryants said her husband had reached a valid agreement with the woman in January to rent the house.