Estonia reinforced its barricades and parliamentary guards Friday for fear of a crackdown like the one the Kremlin is carrying out on its separatist Baltic neighbors.

Friday was a day of mourning in Estonia for four people killed on Sunday in Latvia by Soviet troops who stormed the republic's police headquarters. A Soviet attack on a broadcast station in Lithuania on Jan. 13 killed 14 people.Reins Koov, an aide to Estonian Prime Minister Edgar Savisaar, said he had information that specially trained Soviet troops from the heavily guarded Dvigatel factory in Tallinn, Estonia's capital, were preparing a weekend attack on installations in the republic.

But leaders at the plant disputed the claim. But Vladimir Roednaya, head of the factory workers' collective, acknowledged that "we do have a unit of soldiers under the direct command of the army."