On 15th April 1961 the anti-revolutionary forces bombed the airports of San Antonio de los Baños, Ciudad Libertad, and Santiago de Cuba in an attempt to eliminate the Cuban air force. This incident portended an imminent invasion. On the next day, while the victims of the bombing were being buried, Fidel Castro proclaimed the state of war. On the morning of 17th April mercenaries went ashore at Bay of Pigs, and proceeded to occupy two centrally situated places: Playa Larga and Playa Girón. Meanwhile, paratroopers landed north of this area in order to control the only access roads to these two beaches, which ran through the Zapata swamp. Thus, the occupiers created a centre of force in Bay of Pigs and appointed a provisional government. They intended to take over power by fighting a war of attrition, with the aid of the U.S.