The Netherlands barred Turkish ministers from speaking in Rotterdam on Saturday in a row over Ankara's political campaigning among Turkish emigres, leading President Tayyip Erdogan to brand its fellow NATO member a "Nazi remnant".
The dispute escalated into a major diplomatic incident in the evening, as Turkey's family minister was prevented by police from entering the Turkish consulate in Rotterdam. Hundreds of protesters waving Turkish flags gathered outside, demanding to see the minister.
Dutch police used dogs and water cannon early on Sunday to disperse the crowd, which threw bottles and stones. Several demonstrators were beaten by police with batons, a Reuters witness said. They carried out charges on horseback, while officers advanced on foot with shields and armoured vans.
Less than a day after Dutch authorities prevented Foreign Minister Mevlut Cavusoglu from flying to Rotterdam, Turkey's family minister, Fatma Betul Sayan Kaya, said on Twitter she was being escorted back to Germany.
"The world must take a stance in the name of democracy against this fascist act! This behaviour against a female minister can never be accepted," she said. The Rotterdam mayor confirmed she was being escorted by police to the German border.
The Dutch government, which stands to lose heavily to the anti-Islam party of Geert Wilders in elections next week, said it considered the visits undesirable and "the Netherlands could not cooperate in the public political campaigning of Turkish ministers in the Netherlands."
The government said it saw the potential to import divisions into its own Turkish minority, which has both pro- and anti-Erdogan camps. Dutch politicians across the spectrum said they supported Prime Minister Mark Rutte's decision to ban the visits.
Turkey's Foreign Ministry said it did not want the Dutch ambassador to Ankara to return from leave "for some time". Turkish authorities sealed off the Dutch embassy in Ankara and consulate in Istanbul in apparent retaliation and hundreds gathered there for protests at the Dutch action.
Erdogan is looking to the large number of emigre Turks living in Europe, especially in Germany and the Netherlands, to help clinch victory next month in a referendum that would give the presidency sweeping new powers.
German Chancellor Angela Merkel has said she will do everything possible to prevent Turkish political tensions spilling onto German soil. Four rallies in Austria and one in Switzerland have been cancelled due to the growing dispute.
Erdogan has cited domestic threats from Kurdish and Islamist militants and a July coup bid as cause to vote "yes" to his new powers. But he has also drawn on the emotionally charged row with Europe to portray Turkey as betrayed by allies while facing wars on its southern borders.
The Dutch government had banned Turkish Foreign Minister Mevlut Cavusoglu from attending a rally on Saturday in Rotterdam but he said he would fly there anyway, saying Europe must be rid of its "boss-like attitude".
Cavusoglu, who was barred from a similar meeting in Hamburg last week but spoke instead from the Turkish consulate, accused the Dutch of treating the many Turkish citizens in the country like hostages, cutting them off from Ankara.
"If my going will increase tensions, let it be ... I am a foreign minister and I can go wherever I want," he added hours before his planned flight to Rotterdam was banned.