Group of 20 (G20) protests on Friday erupted in violence in Hamburg, Germany, according to The Guardian.
Masked demonstrators reportedly set fire to at least 20 cars early that morning, moving through Hamburg’s Altona district and pelting area bank and shop windows with rocks.
Hamburg authorities later Friday afternoon purportedly confirmed 160 police officers had been injured and 70 protesters arrested.
Organizers of Thursday’s “Welcome to Hell” march, meanwhile, reportedly said 14 participants were hospitalized, three with serious injuries and another claiming to be in critical condition.
Some Twitter users on Friday voiced alarmed over the chaos, which came on the first day of this year’s G20 Summit.
The G20 is a global forum for the governments and central banks of the world’s 20 largest economies.
Hamburg reportedly boasts 20,000 police officers monitoring this year’s edition of the event, which runs Friday and Saturday.
The 2017 G20 is especially tense due to the presence of controversial leaders like President Trump, Russian President Vladimir Putin and Turkish President Recep Tayyip Erdogan.
Trump and Putin met for the first time in-person Friday, reportedly speaking for two hours and 16 minutes rather than an originally scheduled 30 minutes.
Secretary of State Rex Tillerson said that Trump “pressed” Putin on Russian meddling in the 2016 presidential election in the U.S.
“[They] had a very robust and lengthy exchange on the subject,” he said, adding Putin denied Russia interfered in last year’s race.