BRUSSELS (AP) — Farmers disrupted traffic around Europe’s second biggest port of Antwerp and two other Belgian harbors Thursday during yet another demonstration to protest against what they say is excessive environmental rulemaking.

Dozens of tractors disrupted morning rush hour traffic to and from the harbor facilities, though they shied away from a full blockade following warnings by port authorities they would hold them legally liable for suffered losses.

Farmers from across the 27-nation European Union have protested against what they see as unnecessary bureaucratic rules, clean-air and soil targets and unfair competition from abroad that, they say, is driving them toward bankruptcy. EU nations and environmentalists have said a thorough revamp of the way the EU farms is necessary to contain climate change and pollution and meet global green targets.

The farmers counter that their sector is unfairly singled out and that more measures should be targeted at industry instead.

Last week, Poland saw its most violent protest by farmers and supporters yet as some participants threw stones at police and tried to push through barriers around parliament, injuring several officers. Last month, f armers clashed with police in Belgium outside EU headquarters in a show of force as the European Union’s agriculture ministers met in search of ways to address the protesters’ concerns.

The tractor protests have had a stunning impact on political decision-making. At national and EU levels, several concessions toward the farmers have already been made, angering environmentalists.