Farmers descended on Brussels to press a summit of European Union leaders to do more to help them with taxes, rising costs and cheap imports, throwing eggs at the European Parliament, starting fires near the building and setting off fireworks.
Major thoroughfares in Brussels, the heart of the European Union, were blocked by around 1,000 tractors, according to a police estimate.
One tractor displayed a banner saying "If you love the earth, support those who manage it" as farmers from Belgium and other European countries try to make themselves heard by EU leaders meeting later.
Another banner read: "No farmers, no food."
Security personnel in riot gear stood guard behind barriers where the leaders are due to meet, a few blocks away from the European Parliament building where tractors were parked in a central square.
"If you see with how many people we are here today, and if you see it's all over Europe, so you must have hope. We must have hope that these people see that farming is necessary. It's the food, you know," said Kevin Bertens, a farmer from just outside Brussels.
Farmers say they are not being paid enough, are choked by taxes and green rules and face unfair competition from abroad.
They have already secured several measures, including the bloc's executive commission proposals to limit farm imports from Ukraine and loosen some environmental regulations on fallow lands.
In France, where farmers have been protesting for weeks, the government has dropped plans to gradually reduce subsidies on agricultural diesel and promised more aid.
But farmers say that is not enough, and protests have spread to countries including Belgium, Italy, Spain and Portugal.
Mercosur trade talks
The protests across Europe come ahead of European Parliament elections in June in which the far right, for whom farmers represent a growing constituency, is seen making gains.
While the farmers' crisis is not officially on the agenda of the EU summit, it is bound to be discussed, at least on the margins.
Already, with all eyes on Viktor Orban as the other 26 EU leaders want to convince him at the summit to join a plan to offer stable financing to Ukraine, the Hungarian Prime Minister made a point of meeting farmers overnight.
"We need to find new leaders who truly represent the interests of the people," his spokesman quoted him as saying, referring to the European Parliament elections.
"The @EU_Commission should represent the interests of European farmers against those of Ukraine, not the other way around," he quoted Orban as saying.
As he arrived at the summit, Belgian Prime Minister Alexander De Croo said farmers' grievances should be discussed.
"They offer products of high quality, we also need to make sure that they can get the right price for the high quality products that they provide," he said.
Meanwhile, Irish Prime Minister Leo Varadkar echoed French resident Emmanuel Macron's opposition to signing a trade deal with the Mercosur group of South American countries in its current form - another key demand for farmers.
In France, where farmers stepped up protests at the start of the week, the impact of dozens of blockades is starting to be felt, said Eric Hemar, the head of a federation of transport and logistics employers.
"We did a poll among our federation members: all transport firms are impacted (by the farmers' protest) and have lost over the past 10 days about 30% of their revenue, because we are not able to deliver on time or with delays," he told franceinfo broadcaster.
