President Barack Obama’s final tour as president is in full swing in Athens, Greece, where anti-American protests are in full swing as well.

Youth in the streets of Athens have protested in motorcycle helmets and gas masks, armed with wooden bats and bottle bombs. They have tried to break the barrier of police buses placed by riot officers. The rioters retired to the Athens Polytechnic university complex in the center of the city. They’ve engaged in starting street fights with the government enforcement.

Obama’s visit is just two days before Greece’s annual anti-American exhibitions. These riots commemorate the bloody suppression, by military authorities, of the Polytechnic pro-democracy uprising.

Obama is reassuring foreign leaders that the U.S. will not abandon its alliance obligations despite Trump’s tough campaign.