P503 503 TELEINF 03:32:17 admitted to the Central Clinical Hospital Thursday for medical tests ahead of a heart bypass operation due to take place at the end of this month or in early October. The Kremlin announced Tuesday that Yeltsin would probably remain in hospital until the weekend. Referring to Lebed's peace efforts in Chechnya, Chubais said: "All of us -- Lebed, Chernomyrdin and Chubais -- must do our best to prevent an explosion. This is our main task." While backing Lebed for having stopped the fighting in Chechnya, Chernomyrdin has said he disagrees with elements of the peace deal Lebed signed with the chechen separatists on August 31. Yeltsin himself has voiced only lukewarm support for Lebed's peace efforts. NOVY ATAGI, RUSSIA - Russian envoy Alexander Ljbed said that russian see njxt page >>>