There were serious clashes in central Naples between Eintracht Frankfurt fans and police ahead of the German team’s Champions League match against Napoli on Wednesday.

Car windows were smashed and fans threw flares, chairs and other objects as innocent bystanders sought shelter in bars and restaurants. A police car and other vehicles were set on fire.

Police in riot gear eventually managed to calm the situation and herded the fans onto buses to take them to their hotels.

Further clashes were avoided as the majority of Napoli “ultras” – the local team’s own hardcore fans – were stopped from coming into contact with the German fans. However, they threw stones and bottles at the buses.

The mayor of Naples, Gaetano Manfredi, said the incident created “an unacceptable climate of guerrilla warfare” in the city.

German Interior Minister Nancy Faeser took to Twitter to condemn the clashes, saying “Violence and hooligans are ruining the sport.”

There were no immediate reports of arrests or injuries.

Police had been on high alert in the Italian city – around 800 officers had been deployed – as more than 600 fans arrived from Germany despite Frankfurt fans being prevented from buying tickets following unrest between supporters during the first leg in Germany.