RADIO AND OPTICAL FOLLOW-UP OBSERVATIONS AND IMPROVED INTERPLANETARY NETWORK POSITION OF GRB-970111

We report on Westerbork 840 MHz and 1.4 and 5 GHz radio observations o f the improved Interplanetary Network Wide Field Camera (IPN WFC) erro r box of the gamma-ray burst GRB 970111, between 26.4 hr and 120 days after the event onset. In the similar to 13 arcmin(2) area defined by the IPN (BATSE and Ulysses) annulus and the published refined BeppoSAX WFC error box, we detected no steady sources brighter than 0.56 mJy ( 4 sigma) and no varying radio emission, down to 1.0 mJy (4 sigma). We also report on B-, V-, R-, and I-band observations of the error box wi th the 4.2 m William Herschel Telescope at La Palma.