To the company's disappointment, this first agreement did not bring an end to problems with fishermen. Since Chisso had switched the wastewater output from Minamata Bay to the mouth of Minamata River in September 1958 the environmental damage had spread even further up and down the Shiranui Sea. Cats had started to die in Ashikita to the north and in Izumi to the south of Minamata and new Minamata disease patients were also appearing. The pollution was having a widespread effect on fishing catches and fish sales as people's confidence in the safety of their food evaporated. This drove the Kumamoto Prefectural Alliance of Fishing Cooperatives to take action of a similar pattern to that taken by the Minamata Fishing Alliance earlier in the year, but on a larger scale. On 17 October, 1,500 fishermen from the alliance descended on the factory demanding direct negotiations with Chisso. When company officials refused, the fishermen forced their way into the factory and attacked the security office, breaking windows and injuring seven guards. Alliance president Ushita Murakami delivered their demands to company manager Nishida, who promised a prompt reply. When the response came, the company said that since the factory's waste had still not been proven as the cause of Minamata disease, and it could offer the fishermen nothing.