Hisba is the name used to refer collectively to gangs of Islamic fundamentalist vigilantes in Northern Nigeria, who take it upon themselves to oversee the implementation of Islamic law, or Sharia, in the region. After years of violence between different religious and ethnic groups, the Nigerian central government has opted to allow the Northern part of the country to adopt Sharia. In Sharia states such as Kano, the Hisba can reprimand, arrest, or even beat Nigerians caught violating the law. Punishable offenses include drinking or selling alcohol, having premarital sex (most often revealed when the women gets pregnant), or soliciting a prostitute. Hisba members also ensure that the buses in Northern Nigeria are segregated by gender. Although the methods of the Hisba are often violent and arbitrary, the military and official police turn a blind eye towards their activities. Nigerian President Olusegun Obasanjo has declined to interfere in either the Sharia controversy, or the Hisba issues, because of the intense emotions on both sides.