Russian forces attack locomotive repair plant in Zaporizhzhia / Russian forces advance in downtown Chasov Yar, expert says / New NATO members automatically become targets for Russian forces -- Medvedev / Moscow's spring offensive begins. Russian forces launch their first major operation since the battle for Sudzha with a thrust toward Kostiantynivka / Russian forces deploy "creeping advance" tactics in Zaporizhzhia Oblast / Russian forces make gains in DPR, strengthen positions -- official / Russian forces liberate Rubanshchina, Zaoleshenka in Kursk Region / Russian forces advance in village near border between DPR, Zaporozhye Region / Russian forces prevent Ukrainian breakthrough in DPR -- military expert / Russian forces in final stage of liberating Lugansk region, expert says