Both the government regular armed forces and notorious militia (known as the People's Defense Forces, PDF) were used to attack and raid villages in the South and the Nuba Mountains. Sudan's governments have a long history of using proxies in Southern Sudan, and the North–South border areas, to fight their wars and preserve their regular forces. These militias were recruited locally, and with covert ties to the national government. Many of the Khartoum-aligned groups were created and then armed by the NIF in a deliberate 'divide and rule' strategy. The widespread activity of insurgent and pro-government militants and increasing lawlessness in southern Sudan resulted in the militarization of many communities. Ethnic violence became widespread, and all sides targeted civilians to destroy the power bases and recruitment centers of their rivals. Those who could formed self-defense groups, and these were often based on familial and tribal links as these were the only ones most southern people could still rely on. In this way, groups like the Nuer White Army and Dinka "Titweng" ("cattle guard") militias came into existence. Even though they were originally intended to just defend civilian communities, they often became brutal gangs which targeted civilians of other ethnicities. The government and rebel groups exploited these tensions and self-defense groups, using them to destabilize their enemies.