On Saturday, 5 December 1998, at about 7 p.m., hundreds of people started to gather in the southern part of Blora around the house of Eddy Kosasih, a Chinese merchant who was the largest fertiliser retailer in the district. Attached to his house were a pharmacy and a warehouse containing tons of fertiliser. As the crowd formed, passers-by stopped to watch. News of a possible riot spread fast throughout the town, causing the curious to wonder what was about to happen in their normally peaceful town.

By the time the police arrived at just after 8 p.m. it was too late to calm down the masses. The crowd already numbered in the thousands and emotions were running high. At 8.20 p.m., shouting loudly, they approached the house, broke down the iron gate and began to ransack the compound. They looted and destroyed the warehouse, taking fertiliser, seed, pesticide and other equipment, and burned two trucks loaded with fertiliser. The action did not stop until almost 1.00 p.m. the following day when the army arrived to help the police. On the same evening, a fertiliser warehouse about 10 kilometres to the west of Blora belonging to the Banjareja Kecamatan Cooperative was also ransacked. Interestingly, not a single person was hurt in the mass action. No one was arrested.

The riots continued for three more days. Although fertiliser depots remained the main target, the rioters also attacked shops, especially those along the main roads belonging to Chinese merchants. When the mob swarmed to the police station to demand the release of three rioters detained on 7 December, the police had little choice but to release them without charge. The military, however, took firmer measures, shooting at rioters with rubber bullets when they began to threaten property. By the evening of 9 December the situation was under control, although the atmosphere remained tense. Shop owners took the precaution of removing portable merchandise such as electronic appliances and clothing from their shops. All shops and warehouses storing fertiliser were guarded by the security apparatus but were left open to make sure that what was inside was on public display.