Frustrated at negotiations with the Republic and believing it weakened by both the Darul Islam and Madiun insurgencies, the Dutch launched a military offensive on 19 December 1948 which it termed 'Operatie Kraai' (Operation Crow). By the following day it had conquered the city of Yogyakarta, the location of the temporary Republican capital. By the end of December, all major Republican held cities in Java and Sumatra were in Dutch hands. The Republican President, Vice-President, and all but six Republic of Indonesia ministers were captured by Dutch troops and exiled on Bangka Island off the east coast of Sumatra. In areas surrounding Yogyakarta and Surakarta, Republican forces refused to surrender and continued to wage a guerrilla war under the leadership of Republican military chief of staff General Sudirman who had escaped the Dutch offensives. An emergency Republican government, the Pemerintahan Darurat Republik Indonesia (PDRI), was established in West Sumatra.