DHAKA (AFP) - At least 600,000 people have been stranded and some 14,000 are sheltering in relief centres after floods across Bangladesh dramatically worsened, a minister said on Sunday. Disaster management minister A.M. Shawkat Ali told AFP that the army had been called in to help rescue efforts in the worst hit districts as the number of trapped people soared. "So far 23 districts have been affected by flooding. Some 14,000 people in the worst-affected Sirajaganj and Bogra districts took shelters in relief centres," he said. Relief chief Zillur Rahman said the Jamuna River had breached its banks in Bogra and washed away dozens of villages. Interim government head Fakhruddin Ahmed visited affected areas on Sunday morning and distributed relief among the victims, he said. Bangladesh is criss-crossed by a network of 230 rivers, most of them tributaries of the Ganges and Brahmaputra. The low-lying country suffers annual floods, with at least a fifth of the country submerged each year.