Radio played an important role during the Bangladesh Liberation War of 1971. On March 26, 1971, the broadcasting centre of Radio Pakistan was used to transmit a declaration of independence, which was picked up by a Japanese ship in Chittagong Harbor and got retransmitted. During the war, the Pakistan Army took over the Radio Station in Dhaka and the Bangladeshis operated "Swadhin Bangla Betar Kendra" (Independent Bengal Radio Station) clandestinely. Because of heavy shelling, the station had to be relocated several times, and ultimately moved to Calcutta on May 25, from where it would broadcast until the end of the war. On December 6, 1971 the station was renamed Bangladesh Betar. It continued to operate as the only state-owned radio station of the country. In 1975, after the coup d'état the station was renamed as Radio Bangladesh.