VILNIUS, U.S.S.R., JAN. 15 -- Pro-Moscow Communists called for the overthrow of elected legislatures in all three Soviet Baltic republics today as lawmakers barricaded themselves inside their buildings in fear of military attack.

In Moscow, President Mikhail Gorbachev also stepped up his attacks on leaders of the three secessionist republics, saying his office has been inundated by telegrams from indignant citizens there urging him to take decisive action to restore order. He also lashed out at Russian President Boris Yeltsin for suggesting that Russia, the largest by far of the 15 Soviet republics, might consider forming its own army to defend its newly declared sovereignty.

Today's developments suggested that the crisis triggered Sunday by the violent army takeover of a televison station in Lithuania -- and the claim by a clandestine group called the National Salvation Committee that it had seized power there -- has yet to peak. Indeed, the crisis has broadened to include all three Baltic republics -- Lithuania, Latvian and Estonia -- which were annexed by the Soviet Union in 1940 under secret agreements with Nazi Germany.

Arguing that the Kremlin has timed the final crackdown on Baltic independence movements to coincide with the start of hostilities in the Persian Gulf, Lithuanian President Vytautas Landsbergis called on Western nations today to postpone military action against Iraq "for a few days."

Mavriks Volfson, a Latvian member of the Soviet legislature in Moscow, agreed, declaring that the army operations in the Baltics were elaborately planned and precisely scheduled by military and Kremlin officials to minimize world condemnation. "They are hoping that thousands of deaths in the gulf will overshadow a few deaths in the Baltics," he said.

In Latvia and Estonia, leaders of pro-Moscow Communist Party factions addressed mass rallies of predominantly Russian workers today to demand the immediate resignation of legislatures elected a year ago in the first free voting in the republics in half a century. They accused the legislatures of planning to restore a "bourgeois social order" and implementing discriminatory policies against the non-indigenous population.

Speaking to about 12,000 people gathered at a sports stadium in Riga, the Latvian capital, local Communist chief Alfred Rubiks called for a general strike in the republic and a shutdown of all plane and rail traffic there to force closure of the Latvian legislature. "Our mission is to keep Latvia in the Soviet Union," he said.

"Today is a critical day. We call on the army to restore order and prevent bloodshed. The {pro-Moscow Communists} should take power immediately," declared Lt. Col. Viktor Alksnis, a member of the Soviet legislature representing troops stationed in Latvia.

Earlier today, anti-terrorist units of the Soviet Interior Ministry raided a police academy outside Riga, disarmed a number of cadets and seized ammunition stores. A similar raid took place in Lithuania last week, just before the army takeover of the television station.

Here in the Lithuanian capital, the National Salvation Committee charged in a statement that the legislature had adopted laws that would unleash "military action" against the army and "physical destruction" of Communists, non-Lithuanians and the families of military personnel. The group, whose membership remains unclear, warned it would take the "most decisive measures in reply" to the slightest provocation.

The warning from the committee, which is widely assumed to be an arm of the pro-Moscow wing of the Lithuanian Communist Party, could set the stage for seizure of the legislature building by Soviet paratroops, independence activists here fear. The committee statement was accompanied by an appeal to Gorbachev to institute direct presidential rule in Lithuania, saying that neither the committee nor the legislature is capable of restoring order.

A four-man investigating panel sent to Vilnius by the Federation Council -- the top Soviet executive body -- returned to Moscow this evening with no easing of tensions here, and Lithuanian Deputy Prime Minister Romualdas Ozolas said that its main purpose seemed to be to gather arguments to persuade Gorbachev to impose presidential rule in Lithuania.

Under an emergency measure adopted last year by the Soviet legislature, Gorbachev has the right to take draconian steps to ensure public order in the event of a threat to the security of Soviet citizens or the state. He can ban public meetings and strikes, cut communications, impose curfews, restrict the movements of citizens and suspend democratically elected institutions.

Meanwhile, Lithuanian workers strengthened defenses around the legislature building, using cranes to hoist huge blocks of reinforced concrete into position as tank barricades. Several thousand Lithuanians also kept watch in front of the building, huddling around fires to keep warm in snow-covered Independence Square.

At a Vilnius sports arena, tens of thousands of Lithuanians filed past the flower-strewn coffins of 10 of the 13 civilians known to have been killed Sunday during the army attack on the television station. The mother of one of the victims, Wanda Juknevicus, described the huge crowds as "a referendum of support" for democracy in Lithuania. The dead are to be buried Wednesday in a public funeral.

As many as 80 people are believed still missing after Sunday's army assault, a Lithuanian legislator said, and local officials have been pressing the Soviet military to allow them to conduct a thorough search of the television building.

One of the 14 dead was identified on state television tonight as Soviet paratrooper Viktor Shachshik, who was said to have been killed outside the Vilnius station by a bullet fired from an automatic assault rifle of the kind issued to Soviet troops. Communist officials here said that the soldier was shot by Lithuanian activists, but Western reporters at the scene said they saw no such weapons in the hands of Lithuanians.

The Associated Press added from Moscow:

Gorbachev, in a fiery speech to the Soviet legislature, was speaking of the need for negotiating ways of disarming civilians who have amassed weapons to defend themselves in the republics.

Suddenly, a member of the body, Col. Nikolai Petrushenko, stood up stiffly, pumped his right arm up and down and shouted: "No negotiations! The bandits must be disarmed tonight!"

Gorbachev, who has been under pressure from hard-liners such as Petrushenko to take tougher steps to restore order, shot back angrily: "Before you stands a man who understands the full responsibility and full acuteness of this problem. It's not easy to do this. There are thousands, tens of thousands of weapons. You could start such a slaughter."