This first part of the offensive punched a huge hole in the front, created a salient from Belchite to Caspe to Alcañiz and back to Montalbán. The Nationalist Army now paused before the Ebro and Guadalupe Rivers to reorganize. But on March 22, the attack started again, this time in the area east of Zaragoza and Huesca. This part of the front that the Republic had held since August 1936, was lost in one day. The villages in eastern Aragon that had experienced social revolution, either by their own actions or from the anarchist columns from Catalonia, were all taken by the Nationalists, with many of the inhabitants becoming refugees. In this part of the offensive, Barbastro, Bujaraloz and Sariñena succumbed to the Nationalists. On March 25, Yagüe took Fraga and entered Catalonia. He attacked the next town, Lleida, but El Campesino held him off for a week, giving the Republicans a chance to withdraw with valuable equipment. The retreat of the Republican forces was covered by Colonel Durán's Mountain Group in the Maestrazgo, the rugged mountainous area of southern Aragon. In the north, Republican forces pinned Solchaga down in the Pyrenees, but in the south, the Nationalists drove across the Maestrazgo. Almost everywhere, the Republicans started to fall apart. The various factions started to accuse each other of treachery. The Communists starved anarchist troops of needed munitions. André Marty, the overall commander of the International Brigades, travelled around looking for traitors, but he could not prevent the virtual destruction of the International Brigades. Republican troops suffered arbitrary executions with officers sometimes being shot in front of their men. In general, the campaign seemed lost, and nobody knew where the rout would end. End of the campaign The campaign was decided by air power. The plains of Aragon provided easy landing fields allowing rapid air support from close behind the front. Nationalist aircraft continually drove back the Republicans, forcing them to abandon position after position and attacked the retreating columns. Both Germans and Soviets learned valuable lessons in this conflict about the use of aircraft in support of infantry. On the ground, Lleida and Gandesa fell on April. One hundred and forty American and British soldiers from the XV International Brigade became prisoners of the Nationalists. Also on this day, Aranda's troops saw the sea for the first time. In the north, the Nationalist advance continued and by April 8,