Turkey promises harsh retaliation after Netherlands bars ministers

* Dutch bar Turkish foreign minister's flight from landing

* Protests in Rotterdam, Istanbul and Ankara

* Turkey's Erdogan slams Netherlands, PM vows retaliation

By Tuvan Gumrukcu and Thomas Escritt

ANKARA/ROTTERDAM, March 12 (Reuters) - Turkey told the Netherlands on Sunday that it would retaliate in the "harshest ways" after Turkish ministers were barred from speaking in Rotterdam, as a row over Ankara's political campaigning among Turkish immigrants escalated.

President Tayyip Erdogan labeled the Netherlands a "Nazi remnant" after it became the latest European country worried about political tensions inside Turkey spilling beyond its borders to prevent Turkish politicians from holding rallies.

The Dutch government on Saturday first barred Turkish Foreign Minister Mevlut Cavusoglu from flying to Rotterdam and later stopped Family Minister Fatma Betul Sayan Kaya from entering the Turkish consulate in the port city, before escorting her out of the country to Germany.

Dutch police used dogs and water canon early on Sunday to disperse hundreds of protesters outside the consulate in Rotterdam who were waving Turkish flags and throwing bottles and stones.

Several demonstrators were beaten by police with batons, a Reuters witness said. Officers carried out charges on horseback.

The Dutch government, which stands to lose heavily to the anti-Islam party of Geert Wilders in elections next week, said the ministers' visits were undesirable and that it would not cooperate in the political campaigning of Turkish ministers in the Netherlands.

In a statement issued early on Sunday, Turkish Prime Minister Binali Yildirim said Turkey would retaliate in the "harshest ways" and "respond in kind to this unacceptable behaviour".

Protesters also gathered outside the Dutch embassy in Ankara and consulate in Istanbul, throwing eggs and stones at the buildings. Turkish authorities had earlier sealed off the premises in apparent retaliation.

Dutch Prime Minister Mark Rutte said he would do everything to "de-escalate" the diplomatic confrontation, which he described as the worst the Netherlands had experienced in years.

For a short period, the Turkish flag flew outside the Dutch consulate in Istanbul. Sources inside the Turkish presidency said the flags had been changed by Dutch consulate officials and that there had been no outside interference.

WILDERS: "GO AWAY"

Ahead of his planned trip, Cavusoglu had threatened tough economic and political sanctions against the Netherlands if it refused him entry.

Supporting Rutte's decision to ban the visits, the Dutch government said there was a risk of Turkish political divisions flowing over into its own Turkish minority, which has both pro- and anti-Erdogan camps.