WARSAW, POLAND -- Poland's new agriculture minister vowed Wednesday to introduce detailed quality controls on the massive inflow of grain from Ukraine transiting through the country, and to ensure its efficient transport abroad. The move follows protests by angry Polish farmers, who say they face bankruptcy because of a glut of cheap Ukrainian grain.

Minister Robert Telus faced sharp criticism from lawmakers in parliament, who alleged that trading companies linked to the government were making huge profits from selling cheap, untested Ukrainian produce in Poland, instead of facilitating its transfer to grain-hungry Africa.

Telus replaced the previous agriculture minister, Henryk Kowalczyk, who resigned last week just hours before an official visit by Ukrainian President Volodymyr Zelenskyy. During the visit, the Polish and Ukrainian leaders said they had found a rapid resolution to the "grain problem" but provided no details.

Amid the Russian invasion that has blocked traditional export sea passages, the European Union lifted duties on Ukrainian grain to facilitate its transport to Africa and the Middle East. However, it has flooded markets in Poland, Romania and other EU countries that were only supposed to be transit routes.

Polish farmer groups staged protests Wednesday at border crossings with Ukraine, but police prevented them from blocking the rail tracks. Dozens of cargo wagons, each containing some 70 tons of grain, enter from Ukraine each day, further increasing farmers' anxiety for the future and for their crops this year.

Protesters said the grain transit should be prioritized in the same way as the heavily guarded transshipment of arms to Ukraine, to prevent the grain from flooding the Polish market.

Instead, they argued, government-linked companies were allowed to import it as cheap, low-quality grain, and then sell it to bread and pasta plants as high-quality Polish produce.

Tomasz Obszanski, of the farmers' Solidarity union said some three million tons of grain intended for Africa "were instead received by traders, once they crossed the border into Poland. Many companies have used this situation to make millions."

The leader of the protesting farmers and head of the AgroUnia group, Michal Kolodziejczak, estimated farmers' losses at up to 10 billion zlotys (US$2.3 billion).

"A number of companies linked to the (governing) Law and Justice (party) made huge gains, but ordinary people suffered losses. ... This is absurd," Kolodziejczak said on Radio RMF FM from Hrubieszow, the site of the protest.

He called on the government to urgently press the EU to reintroduce customs dues on Ukrainian grain, corn, poultry, eggs and other farm produce.

Kolodziejczak also urged parliament to investigate whether the agriculture ministry and government authorities were responsible for having ignored a problem farmers had been warning of since last summer.

Prosecutors in the region of eastern Poland bordering Ukraine are investigating allegations that dozens of tons of Ukrainian grain in transit were sold to Polish food plants.

Telus and Ukraine's agrarian policy minister, Mykola Solskyi, said they had suspended Ukrainian grain imports to Poland for domestic consumption and would take steps to ensure it only transited to third countries.

Kolodziejczak said trains were still unloading in Poland on Wednesday.