BERLIN, May 29 (Xinhua) -- European police forces are conducting a coordinated large-scale raid in connection to the 2017 G20 summit in Hamburg, state prosecutors and police in the Northern German city confirmed on Tuesday.

German media reported that police in Italy, Spain, France and Switzerland had begun to raid several premises associated with far-left activists in the early morning. They hereby responded to a formal request from their German colleagues to offer assistance in the course of investigations into violent riots which accompanied the G20 summit.

A special investigatory commission in Germany called "Schwarzer Block" (a reference to the name of a radical subgroup of demonstrators) is being supported by a multinational police force, as well as the European Union's Eurojust agency in Den Haag.

The German Federal Criminal Police Office (BKA) recently launched a European-wide investigation into 24 key suspects, asking security forces in 15 countries to help authorities in Germany to identify the suspects in question.

Hamburg's state interior minister Andy Grote (SPD) has likened some incidents of rioting during the G20 summit in the city to terrorism. "This was a concerted criminal operation which approaches the patterns which we would usually describe as terrorist," Grote said. The SPD politician highlighted that some left-wing extremists had demonstrated a willingness to put human lives at risk in the escalating demonstrations.

According to Jan Hieber, director of the "Schwarzer Block" special investigatory commission, around 220 individuals clad in paramilitary gear succeeded in causing 1.5 million euros (1.7 million U.S. dollars) of damage in only 19 minutes during the most notorious of the summit's riots in the Elbchaussee part of Hamburg. The group set cars on fire and attacked police vehicles as well, leading one security officer to draw his weapon. "It could have easily ended with fatalities," Hieber said.

The German public broadcaster NDR reported on Tuesday that the European-wide raids in connection to the Elbchaussee riots were conducted following detailed analysis of live video footage which provided police with a list of key suspects. Additionally, investigators had succeeded in proving the participation of some suspects in violent riots on the basis of DNA probes.

NDR cited information that Italian police searched the flat of a man who has already been sentenced for attacking a police officer during the G20 summit and is also believed to have participated in the Elbchaussee riots. A 27-year-old man was arrested in Switzerland, while French police continued with their hunt for a wanted individual for whom German state prosecutors have issued a European arrest warrant.

Hamburg police estimate that between 5,000 and 6,000 individuals participated in riots over the course of several days, plundering local stores and setting fire to cars, prior to and during the G20 summit of political leaders from the world's major economic powers. 3,200 related investigatory cases are still ongoing, including more than a hundred cases involving allegations of excessive violence used by police.