On the 26th of May 2001, a meeting of far right group Combat 18, football hooligans and a local mob known as the Fine Young Casuals at the Lark public house was broken up by the police at 3pm.
They were dispersed, but then went on to get drunk and agitate and provoke the local mainly **** stani community. Police subsequently arrested 12 people, most of whom had BNP connections. They were later jailed, but their actions sparked the ensuing riots.
http://news.bbc.co.uk/1/hi/england/manchester/ 2989134.stm