VILNIUS, U.S.S.R., JAN. 14 -- Soviet security forces seized at least two radio supply facilities and established numerous roadblocks here today, setting the stage for what could be a prolonged war of nerves in this ancient Baltic capital between Moscow and the secessionist Lithuanian government.

After days of trying, Lithuanian President Vytautas Landsbergis succeeded in reaching Soviet President Mikhail Gorbachev by phone this morning, the first time the two had spoken since an army assault on a television station here early Sunday left 14 civilians dead and scores more wounded. Landsbergis described the conversation, which lasted several minutes, as "not very calm or gentle," but he said there had been some "constructive moments."

Meanwhile, a truce in the immediate vicinity of parliament appeared to be holding, as military authorities relaxed the nighttime curfew imposed two days ago. But the atmosphere inside the heavily barricaded building remained tense, with legislators uncertain if they would be attacked. Some suggested that Soviet paratroops might try to seize the building from the air to avoid a clash with thousands of unarmed civilians outside.

Although there was no sign that Gorbachev was backing down in his determination to reimpose central authority over Lithuania and the other two Soviet Baltic republics, Latvia and Estonia, he seemed to be displaying some flexibility in tactics, alternating force with diplomacy. A four-man investigating delegation from the Federation Council, the Soviet Union's highest executive body, spent the day in emotional meetings with supporters and opponents of Lithuanian independence.

Lithuanian officials say Gorbachev is preparing the ground for direct presidential rule over this republic of 3.4 million people by making it appear a lesser evil to military tyranny or parliamentary anarchy. The ideology chief of the pro-Moscow wing of the Lithuanian Communist Party, Juozas Jermalavicius, called today for the rapid introduction of presidential rule, saying it was the only way to stop "civil war" in the republic.

Presidential rule would allow Gorbachev to suspend all democratically elected institutions in the republic, from the parliament down. To make such a step slightly more palatable to the Lithuanian people, Gorbachev could also abolish the mysterious army-backed National Salvation Committee, which claimed to have seized power and appealed for army support here early Sunday on behalf of "workers and peasants."

The membership of the committee has not been revealed, and there is considerable doubt that it even exists. Jermalavicius said today that the committee was in constant session at a Vilnius electronics plant, but that no outsider knows its precise location. He said he was in touch with the committee "by courier."

According to Jermalavicius, the committee was set up on Saturday by an organization calling itself the "Congress of Democratic Forces." Most leaders of the congress, which held its inaugural session last month, are Communist officials; its president is Mikolas Burokiavicius, head of the local pro-Moscow Communist Party faction.

Jermalavicius accused Lithuanian leaders of drawing up a plan to exterminate all Communists but produced no evidence to support his charges, which reflect the propaganda line now adopted by the Communist Party to justify the crackdown here.

Shortly before midday, Interior Ministry troops seized buildings in Vilnius and Kaunas, the former capital, housing equipment for closed-circuit radio stations still under the control of parliament. By doing so, the military effectively tightened its control over the main information dispensing instruments in the republic, having already seized the television tower and the central publishing plant.

The seizure of the buildings provoked an uproar at a packed meeting between the Federation Council delegation and Lithuanian intellectuals at the Academy of Sciences here. Speakers said the incident showed that the delegation, which includes the presidents of Soviet Armenia and Byelorussia, is effectively powerless despite its declared intention of "stopping the bloodshed."

Chants of "Free Lithuania" greeted members of the delegation as they drove around the city in a motorcade of limousines flying the Soviet and Lithuanian flags. At a Vilnius factory, independence activists held up banners bearing such slogans as "No to Red Terror," while groups of ethnic-Russian and Byelorussian workers demanded dismissal of Landsbergis.

The bodies of 10 of the victims of Sunday's violence -- including a woman in her wedding dress -- were laid out at a Vilnius sports stadium today prior to a mass funeral Wednesday. Flags trimmed with black ribbons flew at half staff throughout the city as Lithuanians observed a three-day period of public mourning for the dead.

Lithuanian officials said that the commander of Soviet ground forces, Gen. Valentin Varennikov, had arrived here from Moscow today to take charge of the military operation. Varennikov, who last month signed an appeal to Gorbachev to impose presidential rule in troubled regions, made his name in the Soviet army during the 10-year war in Afghanistan.

"This appointment does not exactly cause optimism. Varennikov's name is associated with bloodshed and tension," Lithuanian Vice President Kazimieras Motieka told reporters.

To reduce the risk of large-scale bloodshed in any army assault on parliament, Lithuanian leaders today dismissed many guards from the building, around which citizens have formed barricades of heavy trucks and buses. Fires burn all night in the snow-covered streets around the building to keep people warm.

Landsbergis said he had appealed to Gorbachev to allow Lithuanian health officials to inspect buildings seized by the army over the weekend. He said that the Gorbachev honored the request, but that the military still has not allowed Lithuanian officials to see the upper floors of the television station, where it is thought fighting may have occurred.

Military officers have had several rounds of talks with Lithuanian representatives since the violence. This evening, the officers reportedly said that tanks and armored vehicles would not make nighttime sorties into the city but that soldiers patrolling on foot would be equipped with automatic weapons.