Russia attacked Ukraine’s main inland port across the Danube River from Romania on Wednesday, sending global food prices higher as it ramped up its use of force to prevent Ukraine from exporting grain.

The drone attacks destroyed buildings in the port of Izmail and halted ships as they prepared to arrive there to load with Ukrainian grain in defiance of a de-facto blockade Russia reimposed in mid-July.

Ukrainian Deputy Prime Minister Oleksandr Kubrakov said the Russian attacks damaged almost 40,000 tons of grain that had been destined for countries in Africa as well as China and Israel.