Farmers in Poland have intensified protests against cheap food imports from Ukraine, which have flooded into the European Union since the start of the Russia-Ukraine conflict two years ago.

The latest sign that the nation's agricultural sector is becoming increasingly angry came on Tuesday, when thousands of farmers marched through the capital, Warsaw.

The demonstration followed farmers blocking a major highway on Tuesday, at the border between Poland and Germany.

The blockade also highlighted opposition to EU agricultural regulations aimed at tackling climate change, which farmers say are overly oppressive and costly.

The protests mirrored action in many other EU nations in recent weeks.

Adrian Wawrzyniak, a spokesperson for Poland's Solidarity farmers' union, told Reuters the blockade was done in collaboration with farmers in Germany.

"This is a show of common solidarity, that both Polish and German farmers will not allow these goods from Ukraine to continue to enter the European market. It's a common cause," he said.

The farmers' anger has been growing since June 2022, when the EU decided to show its support for Ukraine in the Russia-Ukraine conflict by suspending import duties, quotas, and trade defense measures for imports from Ukraine. Many EU farmers said the policy means they cannot compete.

Poland's Prime Minister Donald Tusk and president, Andrzej Duda, responded to the blockade and Tuesday's protest by calling on the EU to address farmers' concerns, especially in relation to cheap imports.

"Poland is the first EU country (on the border), but, in fact, it is a problem of the EU as a whole, of EU agriculture as a whole, and it should be considered in this context," he said.

The French state-owned news channel France 24 said Polish farmers destroyed around 160 metric tons of Ukrainian grain on the weekend, at a railway station near Bydgoszcz in eastern Poland. The destruction prompted Ukraine's Deputy Prime Minister Oleksandr Kubrakov to write on X on Monday: "Those who have damaged Ukrainian grain must be found, neutralized, and punished. Two friendly civilized European states are interested in this."

Farmers in Spain and France also vented their anger about cheap imports and costly EU agricultural policies on Tuesday, blocking a border crossing with tractors and burning tires. Farmers in Italy and Greece have taken similar action recently.

The widespread unrest was discussed in Brussels, Belgium on Monday, at a meeting of EU agriculture ministers who agreed to dismantle the bloc's green agricultural architecture, cut on-farm checks, and look at restarting subsidies for farmers.