Ukraine called on Poland to punish those responsible for the destruction of 160 tons of Ukrainian grain in an attack on a Polish railway station.

"Kiev has sent a note to Warsaw demanding that the Polish authorities find and punish the culprits," Ukraine's Deputy Prime Minister Oleksandr Kubrakov said on Monday.

"Those who encroached on Ukrainian grain must be found, neutralized and punished. Two friendly civilized European countries are interested in this," Kubrakov wrote.

The official said earlier that 160 tons of grain, bound for other countries through the port of Gdansk, had been dumped at the railway station near Bydgoszcz, in eastern Poland. This is reportedly the fourth case of Ukrainian grain being destroyed by protesting Polish farmers in recent weeks.

Polish farmers have been part of mass protests by European farmers in recent weeks. However, they have been protesting against "unfair competition" from Ukraine for more than a year.

The European Union suspended import duties, quotas and trade protection measures on imports from Ukraine in June 2022 after Russia's war shut down many of the country's usual grain export routes. However, the flow of cheap grain from the east quickly sparked protests by farmers and truckers in neighboring countries.

On Friday, a Ukrainian government delegation visited the border with Poland to discuss the protests.

Prime Minister Denis Schmihal said Kiev had developed a five-step plan "of mutual understanding" to find a compromise for both sides.

"The blockade affects all Polish-Ukrainian trade and the economy of our countries. Not only Ukraine loses from this, but also Polish entrepreneurs, who export goods worth 12 billion dollars a year to our market, lose from this."

He added that Kiev is also ready to implement a mechanism to check the export of grain, corn, sunflower and rapeseed.

Ukrainian President Volodymyr Zelensky said on Sunday that it is important for Kyiv to maintain close relations with Poland. However, he added that his country is ready to protect businesses that have suffered from border blockades.

His Polish counterpart, Andrzej Duda, countered by saying that Poland is firmly behind Ukraine on the war, but the farmers' problems cannot be delayed.

Lately, Ukraine has tried to conflate the two issues, saying blockades of its grain exports have caused severe economic losses and affected its military efforts.

Ukrainian border guard spokesman Andriy Demchenko said on television: "Unfortunately, the blockade continues."

"A total of 2,200 trucks are queuing up on Polish territory, and farmers are passing several vehicles every hour in both directions. Those trucks that come from Ukraine are more blocked," he said.

Beyond Poland, farmers from across Europe, including France, Germany and Belgium, blocked roads and protested against unfair competition, as well as environmental regulations, increased costs and low produce prices.

Tractors surrounded EU headquarters in Brussels on Monday as ministers met to seek ways to streamline farming rules and red tape fueling protests in the bloc.

Farmers burned tires and set off fireworks in the street. Police used water cannons to douse the flames as ministers discussed the changes.