In this frame grab from video provided by Voice of America, members of Turkish President Recep Tayyip Erdogan’s security detail are shown violently reacting to peaceful protesters during Erdogan's trip last month to Washington. (Voice of America via AP)

BERLIN — Turkish bodyguards served with criminal charges for allegedly attacking protesters outside the ambassador's residence in D.C. “won't set foot on German soil in the foreseeable future, so also during the G-20 summit,” a spokesman for the German Foreign Ministry said Monday.

A German official briefed on security matters, who asked not to be identified because he is not authorized to speak about arrangements with foreign governments, said a few of these guards had been on a list prepared by the Turkish Embassy in Germany of individuals scheduled to attend the summit. After the list was received by the German Foreign Ministry, the official said, German federal police and other security personnel communicated to Turkish security that these individuals were not to attend.

Germany is preparing for mass protests when Hamburg, a northern port city, hosts leaders of the world's major economies next month. The annual conference is a favored target of demonstrations, and officials have been rehearsing security scenarios for more than half a year, said Wolfgang Schmidt, state councilor at the Hamburg senate chancellery.

“It will be the biggest police activity in the history of Hamburg,” Schmidt said.

Because Germany is home to the largest Turkish population in the world outside Turkey, one flash point for which authorities have been preparing is a possible clash between Turkish nationalists and Kurds, joined by protesters on the left. Tensions are running high after Turkish President Recep Tayyip Erdogan claimed victory in the spring in a referendum granting him expansive new powers.

The fear is of a repetition, on a large scale, of the skirmish that unfolded in May when, according to D.C. police, members of Erdogan’s security detail descended on protesters at Sheridan Circle, along Massachusetts Avenue’s Embassy Row. Video appeared to show the guards, some of them armed, chasing and beating members of the crowd, with Erdogan looking on. Twelve people have been charged in the incident. Turkish officials, meanwhile, portrayed the guards as victims.

“We saw what happened in Washington,” said David Stachnik, a spokesman for the Hamburg Police. “If it should escalate here, too, we're definitely prepared, but we don't have any specific indication that it will happen.”

The Foreign Ministry would not go into detail about what it had communicated to Turkey, but Martin Schaefer, the ministry's spokesman, said Monday that he could “assume with a good conscience that the people who have been incriminated by the U.S. criminal justice authorities” would not be at next month's conference. The Turkish Embassy did not return a request for comment.

Schmidt, who has been closely involved in planning in Hamburg, said between 50,000 and 100,000 protesters are expected during two days of meetings, as well as the days leading up to the start of the conference on July 7. He said police are expecting up to 8,000 violent protesters on July 6.

Authorities will be equipped with 45 water cannons, and police helicopters from all over Germany will fly overhead, Schmidt said. The summit will take place in two primary locations, a business center and a concert hall, making it possible to cordon off routes to hotels and the airport.

“The overall security concept in Hamburg should prevent any scenes that we have seen in Washington, because as always when a G-20 summit takes place in a democracy, the question is how you protect people's voices while limiting the possibility of an encounter,” Schmidt said.

Ebru Turhan, a political scientist at the Turkish-German University of Istanbul, said the apparent decision by Germany to bar these guards from attending the summit is indicative of a recent period of intense mistrust between the two countries. But she said this was only a “temporary crisis,” as common interests, such as the management of the refugee crisis, as well as the conclusion in September of Germany's federal election, in which criticism of Turkey will be pronounced, will bring the countries back together.

“A vicious cycle of phases of conflict followed by moments of rapprochement has become characteristic of German-Turkish relations,” Turhan said.

Stephanie Kirchner contributed to this report.