A total of 14 formal complaints have now been lodged with German police following a spate of assaults at the Schlossgrabenfest music festival in Darmstadt last weekend. By Tuesday, some 26 women had come forward to say they had been assaulted.

The young women who reported the harassment said they were encircled and groped by groups of men in a series of assaults reminiscent of those at the New Year's Eve festivities in Cologne.

"The women have reported that the [perpetrators] appeared to be men from the South Asia region," police said in a statement.

According to police, three Pakistani men aged 28 to 31 - at least two of whom were asylum seekers - were arrested at the music festival, but later released.

Cologne attacks

The reported assaults in Darmstadt last weekend came six months after a series of attacks on New Year's Eve by gangs of young men outside Cologne central train station.

Investigators in Cologne received 1,170 formal complaints of attacks - 492 of them related to assaults of a sexual nature. Eye witnesses and victims described the perpetrators as being mainly from North Africa and the Arabian peninsula; some were claimed to be Arabic speakers.

Refugee debate

January's attacks were met with shock across Germany and sparked a debate, particularly among far-right parties, over Berlin's decision to accept more than one million asylum-seekers during last year's unprecedented influx of refugees.

In light of the attacks, extra security measures have been implemented at a number of public events, including the Cologne's famous Carnival in February.

Around 360,000 euros ($400,000) were invested into the extra security measures for the six-day event, including an increased police presence, mobile lighting masts to illuminate dark, potentially dangerous corners, and a security point where women could report to in case of an emergency.