Unusually rapid variability of the GRB000301C optical afterglow

We present BV RI light curves of the afterglow of GRB000301C, one of the brightest ever detected at a day time scale interval after GRB trigger. The monitoring started 1.5 days after the GRB and ended one month later. Inspection of the ex- tremely well sampled R band light curve and comparison with BV I data has revealed complex behavior, with a long term flux decrease and various short time scale features superim- posed. These features are uncommon among other observed af- terglows, and might trace either intrinsic variability within the relativistic shock (re-acceleration and re-energization) or inho- mogeneities in the medium in which the shock propagates.