KYIV, Aug 2 (Reuters) - Russia attacked Ukraine's main inland port across the Danube River from Romania on Wednesday, sending global food prices higher as it ramps up its use of force to prevent Ukraine from exporting grain. Ukraine's Danube river ports such as Izmail accounted for around a quarter of grain exports before Russia pulled out of the Black Sea deal, and have since become the main remaining route out, with grain loaded onto barges and shipped to Romania's Black Sea port of Constanta for shipment onwards. Ukrainian officials say Moscow has hit 26 port facilities, five civilian vessels and 180,000 tonnes of grain in nine days of strikes since quitting the grain deal