The crowd had gathered outside the school because they were unhappy with what they considered to be the lack of action against the pupil and attempted to gain entry in order to enforce their own punishment. When police shot a 17 year-old protester in the neck whilst trying to protect the school the crowd turned on local Christians and their property. The incident which had enraged Muslim anger occurred two weeks earlier when a 12 year-old Christian girl reportedly responded to taunts from Muslim classmates by insulting the Islamic prophet Muhammad. At the beginning of November three students were killed when Muslims stormed a private party in Maiduguri University, northeastern Nigeria, where they suspected a beauty pageant was being held. Since it was the women whom the gang initially targeted the incensed Christians fought back. Another campus incident occurred at the Ahmadu Bello University in the northern state of Kaduna on 23 September, when a female Christian student who had been engaged in a religious discussion which turned into an argument was attacked and critically injured. Tensions provoked by the adoption of full Islamic law (shari'a) in twelve states in northern Nigerian since 1999 has led to widespread religious riots in which over 5000 people have been killed.