Scholars have indicated that violence in Xinjiang is based on an assortment of ideologies, and there is no single dominant ideology among the Uyhurs. As James Millward writes, incidents have "been discontinuous and characterized by a variety of ideologies, Islam being only one of them." Islam, Pan-Turkic nationalism, and Uyghur nationalism are all factors in unrest in the Xinjiang region. There are six incidents in China from 1990 to 2005, according to Ogden, that meet the strictest definition of terrorism, meaning the use of "random" violence against innocent civilians to cause terror, and excluding calculated violence against the state to advance a secessionist movement. Among the events identified by Ogden was an incident on 6 February 1992 when Uyghur separatists (possibly belonging to the East Turkestan Islamic Party) detonated a bomb on a public bus in Urumqi, and a bomb attack on a hotel in Kashgar on 17 June 1992. Instances of violence by ethnic Uyghurs against security forces, organs or infrastructure of the state are far more common, but are distinguished by scholars from terrorism aimed against the civilian population. According to Martin, Chinese authorities frequently classify any act of violence or separatist activity in Xinjiang as a manifestation of terrorism, while comparable acts by ethnic Han Chinese would not be classified in this manner.