At least 22 police officers were injured Saturday in unrest in the western German town of Giessen during an Eritrean cultural festival, according to local police.

Police in the German state of Hessen said there were "massive attacks" against their officers early Saturday morning, with demonstrators "throwing stones and bottles and setting off smoke bombs" and attempting "to break through police barriers" into the event site.

"The police had to use pepper spray and batons," Hessen police said in a statement, adding that there were "severe traffic problems in the area" and that there was also damage to cars.

According to CNN affiliates NTV and ZDF, last year there was similar unrest, because the organizers of the festival are thought to be close to the Eritrean regime. Thousands of Eritreans have fled to Europe in recent years, alleging mistreatment at the hands of the current regime.

The city of Giessen attempted to block the festival from taking place this year but the ban was overturned by a local court, according to ZDF.

Hessen police added that around 1,000 officers from various units within the force had been deployed and that the situation was ongoing.

"There are currently no concrete figures on the number of people injured or detained," said Hessen police.

It added that overnight Friday into Saturday around 60 people were detained in suspicion of planning an attack during the event.