Upon independence, there was significant controversy surrounding Islam's role in politics, which had caused enormous tensions. The contentions were mainly surrounding the position of Islam in the constitution of Indonesia. Islamic groups have aspired for the supreme status of Islam within the constitutional framework by the inclusion of the Jakarta Charter, which obliges Muslim to abide by shari'a. The Sukarno regime denied this with the implementation of the more pluralist constitution heeding to the ideology of Pancasila, which deemed as non-Islamic. Eventually, "Indonesia adopted a civil code instead of an Islamic one." However, the struggle for the constitutional amendment continued. The hostility against the Sukarno regime was manifested on various other occasions. Most notably the anti-communist genocide perpetuated actively by Ansor Youth Movement, the youth wing of NU (which was initially supportive of the Sukarno regime) and other Islamic groups. Muslims adhering to the syncretic form of Islam known as "Abangan" had also become the target of this mass killing. Communism was considered hostile by Muslims due to perceived atheistic nature and the tendency of landowners being local Islamic chiefs.