Top wheat importer Egypt was forced to yet again ditch efforts to buy the grain it needs to subsidize bread for its people, highlighting the threat that the Russia-Ukraine war poses to the world’s food needs.

For the second time since Thursday, Egypt scrapped a tender to purchase wheat after drawing just a few offers—at sharply higher prices—as supply worries mount in the wake of Russia’s invasion of its neighbor. Egypt is among countries in the Middle East and North Africa that rely on massive imports to feed their citizens, and Black Sea nations are key suppliers.

Russia and Ukraine together account for more than a quarter of global wheat exports. While Russian commodities are so far exempted from sanctions, traders are being spooked by the fast-moving penalties, surging freight and insurance costs and shipping halts in the region. Restricting grain supplies from the area threatens to further boost global food prices that are near a record. 

Only three companies participated in Egypt’s tender on Monday, with two offers of French wheat and one for U.S. supplies, according to traders who asked not to be identified. That compares with 17 in a tender from mid-February, before the war broke out. Offer prices jumped by at least $80 a ton since then. Egypt’s state buyer cited high prices for the tender cancelation.