As the war continued to rage in Ukraine’s east, much of its Western border was blocked on Tuesday by another fight, this one with Polish farmers.

The farmers have for months been protesting an influx of Ukrainian products that they say is crowding the Polish market and undercutting their livelihood. On Tuesday, they obstructed check points for commercial transportation, halted the passage of about 3,000 Ukrainian trucks and opened some train cars containing Ukrainian grain, spilling it onto the rails.

“It’s either us or them,” a Polish farmer said on Tuesday on the Polish TV channel Polsat News. “Someone must be interested in us.”

The demonstration prompted a counterprotest in Ukraine, where previous blockades by Polish truckers have hampered the supply chain of goods reaching the country, causing shortages that have begun to affect soldiers on the battlefield.

Oleh Nikolenko, a spokesman for the Ukrainian foreign ministry, said that the protests “undermine Ukraine’s economy and its resilience to repel Russian aggression.”

The protests on Tuesday echoed those of other farmers across Europe in recent months, which lamented European Union environmental regulations, and imports that the farmers said were making it hard for them to earn a living.