Turkey's foreign minister warned there "will be repercussions" against the Netherlands and that an "apology was not enough" as tensions continued to escalate Sunday between the two NATO allies, a day after Dutch officials prevented him from holding a political rally in Rotterdam.
The row escalated when the Netherlands withdrew landing permission for Foreign Minister Mevlut Cavusoglu, who had planned to address a gathering of Turkish expatriates in support of his president's referendum campaign for expanded powers. Dutch officials cited public order and security concerns for denying his plane entry.
Later in the day, Dutch officials blocked the car of Turkey's Family Minister Fatma Betul Sayan Kaya from reaching the Turkish consulate in Rotterdam.
She then announced on Twitter that she was being escorted by police to the German border. Kaya later boarded a private plane from the German town of Cologne to return to Istanbul.
Hundreds of protesters waving Turkish flags gathered outside Turkey's consulate in Rotterdam, demanding to see the minister.
Dutch police used dogs and water cannon early Sunday to disperse the crowd, which threw bottles and stones. Several demonstrators were beaten by police with batons, a witness said. Police carried out charges on horseback, while other officers advanced on foot with shields and armoured vans.
On Sunday, Dutch Prime Minister Mark Rutte promised to work toward de-escalating tensions, but also said Turkey should apologize for saying the Dutch are "Nazi remnants."
Rutte said it was important for his government not to bow to Turkish pressure, especially after Ankara threatened sanctions if the Dutch kept its cabinet ministers out.
"Turkey is a proud nation; the Netherlands is a proud nation. We can never do business under those sorts of threats and blackmail," said Rutte.
Noting that Ankara already had barred the Dutch ambassador from returning to Turkey, Cavusoglu added Turkish officials "have other steps in mind. We've already begun planning them. We will certainly take those steps and more."
Cavusoglu also condemned treatment of Turkish protesters in Rotterdam, saying he would show photographs of dogs being released on them.
The barring of two Turkish cabinet ministers from a city with a large number of Turkish immigrants resulted in Turkey sealing off the Dutch embassy in the Turkish capital, Ankara, for "security reasons."
In addition, Turkish President Recep Tayyip Erdogan on Sunday repeated his description of the moves against the rallies as "fascism" and said the Netherlands would "pay the price."
Turkish politicians are seeking to hold campaign events and win votes for the "yes" side in April's referendum on constitutional reforms to strengthen presidential rule in Turkey.
In one diplomatic volley, Turkey told the Netherlands on Sunday that it would retaliate for "unacceptable behaviour" in the "harshest ways" for preventing its politicians from speaking in Rotterdam.
Authorities in Germany, Austria and Switzerland have also recently banned campaign events for the Turkish referendum.
Cavusoglu in France for rally
France, on the other hand, allowed Cavusoglu to hold a political rally in the northeastern French city of Metz on Sunday.
"In the absence of a proven threat to public order, there was no reason to prohibit the meeting," the French foreign ministry said in the statement.
The ministry also urged a "de-escalation" of tensions between Turkey and member states of the European Union.
In Sweden, the owner of a venue in Stockholm, where a senior official from Turkey's ruling party was due to hold a rally on Sunday, cancelled the rental contract, Turkey's private Dogan news agency reported.
The news agency said the owner had not given a reason for the decision.
People in Turkey will vote on the reforms on April 16, with a simple majority needed to approve legislation passed by parliament in January and rubber-stamped by Erdogan last month.
Erdogan says an overhauled political system is needed to tackle unprecedented security threats, from a series of bombings to last July's attempted military coup.
The Turkish president is looking to the large number of emigre Turks living in Europe, especially in Germany and the Netherlands, to help clinch victory in next month's referendum.
"The Dutch government with the obstructions it created has tried to take hostage nearly half-a-million of our citizens and to deny their most fundamental democratic rights," the Turkish government said in a statement.
Netherlands vote on Wednesday
While the Erdogan government works to secure the votes of Turkish expats, a candidate in the national election, the so-called Donald Trump of the Netherlands, has been appealing to anti-immigrant sentiment in the Netherlands.
The Netherlands is set to hold a national election on Wednesday. It has turned into a close race between current Prime Minister Mark Rutte and nationalist Geert Wilders, who has promised to close borders to asylum seekers.
"If you sacrifice Turkish-Dutch relations to the elections that will be held on Wednesday, you will pay the price. You will pay the price. We haven't started to take the necessary steps yet," the Turkish president said on Sunday.
For his part, Rutte said his government "will keep working to de-escalate where we can. If the Turks choose to escalate, we will have to react, but we will do everything we can to de-escalate."
Political scientist Andre Krouwel, of Amsterdam's Free University, said that, in an election campaign dominated by nationalism and national identity issues, Rutte's right-wing VVD party and not the Party for Freedom of anti-Islam firebrand Wilders would likely profit most from the diplomatic showdown with Turkey.
"Rutte is a key player in this because he is prime minister," Krouwel said in a telephone interview with The Associated Press. So he and the VVD can say: "'We are the ones who really protect your interests, we are the ones who go down into the trenches to defend the Netherlands."'