Russian troops have penetrated to the very center of Grozny. But the numerous rebels still in the area make it a dangerous place. Snipers, mines, ambushes and sudden counterattacks make life very difficult for the Russians. The air and artillery bombardment of Grozny and surrounding areas is the heaviest yet, with nearly 200 warplane and attack helicopter sorties a day.  In neighboring Ingushetia, a bomb went off in the provincial capitals supreme court building. A caller with a Chechen accent said the bombing was related to the current murder trial of a Chechen man.