In 2007, militia forces attacked the park's headquarters for its stockpile of 1.5 tons of ivory, and killed three rangers.[7][8] The government of Chad began working with African Parks in 2010 to help manage and protect the park and its wildlife,[6][7][8] especially elephants.[6] The park's anti-poaching strategy includes equipping approximately 60 rangers with GPS tracking units and radios to improve communications, mobility, and safety, as well as improving mobility through the use of horses and other vehicles.[1][9][6] The European Union pledged €6.9m in 2011 to help protect the park for five years.[10]