The United Nations Security Council brokered the Renville Agreement in an attempt to rectify the collapsed Linggarjati Agreement. The agreement was ratified in January 1948 and recognised a cease-fire along the so-called 'Van Mook line'; which connected the most advanced Dutch positions. Many Republican positions, however, were still held behind the Dutch lines. In February 1948 the Siliwangi Division (35,000 men) of the Republican Army, led by Nasution, marched from West Java to Central Java; the relocation was intended to ease internal Republican tensions involving the Division in the Surakarta area. The Battalion, however, clashed with Dutch troops while crossing Mount Slamet, and the Dutch believed it was part of a systematic troop movement across the Renville Line.