BRUSSELS - Dairy farmers created traffic chaos in Berlin, blocked milk processing plants in France and protested at European Union headquarters in Brussels on Monday, seeking more aid to cope with a sharp drop in milk prices.

EU farm ministers opened two days of talks Monday and were expected to discuss ways to increase incomes for dairy farmers. France and Germany have promised to co-ordinate support action to boost milk prices.

Some 6,000 farmers with 700 tractors clogged roads in the German capital, irritating commuters and bringing traffic in some areas to a halt. In response, the German government promised to provide cheaper diesel oil for farmers.

EU farmers say they have been forced to sell milk below cost because prices have fallen by up to 50 per cent over the past year.

At EU headquarters, some 1,000 farmers from half a dozen countries protested with tractors and cows in tow to press their demands for more funds. Police briefly intervened when a few farmers sought to break through the EU's security perimeter but order was quickly restored.

"(We) demand a fair price for our milk, which covers at least our production cost and some profit margin," said Eddie Chinon, a French dairy farmer.

The EU has managed farm prices for decades, guaranteeing minimum prices to farmers or buying up excess production to keep prices artificially high. The EU says it's trying to support dairy prices now by buying skimmed powdered milk and butter on the market - but the 27-member bloc is keen to avoid stockpiling the massive "butter mountains" that made EU farm subsidies notorious in the 1980s.

In France, more than 80 processing plants were closed off Monday by angry farmers demanding more government intervention. The protesters made sure no milk could be collected from farms to be processed into butter and cheese - the second such protest day in a month.

EU Farm Commissioner Mariann Fischer-Boel, meanwhile, had a clear message for the protesters.

"What farmers need to do is produce less," she said Monday.

In January, the EU restarted export refunds to help its farmers sell more abroad - a move echoed by the United States this week. Australia and New Zealand, which do not subsidize dairy exports, say that's unfair trade protectionism.

Under pressure from trade partners, the EU has in recent years tried to drop these farm subsidies and stick to free market principles - often angering European farmers who complain of falling incomes.

To help alleviate the financial strain on milk farmers, the EU Commission is considering to bring forward some subsidy payments from December to October.

"There is a real crisis, a social problem out there on family farms in Europe," said Padraig Walshe, the lead of the COPA farmers' union. "(Farmers) have a problem buying food and clothes."

"There is no profit being made on farms today," he added.