Eighteen women have said they were sexually assaulted at a music festival in Germany.

Three men from Pakistan aged between 28 and 31 have been arrested and police are still searching for three men who may also have been involved.

The attacks are similar to those reported in Cologne and other cities on New Year's Eve, when as many as 1,000 women were groped and robbed.

Police said three women reported being groped at the Schlossgrabenfest music festival in Darmstadt on Saturday, saying they had been encircled then sexually harassed by a group of men.

By Tuesday, 15 more women had made complaints of being sexually assaulted in a similar manner at the festival.

Germany reacts to Cologne New Year's Eve attacks Show all 13 1 /13 Germany reacts to Cologne New Year's Eve attacks Germany reacts to Cologne New Year's Eve attacks Women protest against sexism outside Cologne Cathedral on 5 January after the assaults Oliver Berg/EPA Germany reacts to Cologne New Year's Eve attacks Women protest against sexism in Cologne following the rash of sex attacks on New Year's Eve Wolfgang Rattay/Reuters Germany reacts to Cologne New Year's Eve attacks Police initially failed to mention the assaults in report the following morning EPA Germany reacts to Cologne New Year's Eve attacks Police officers patrol in front of the main station of Cologne, Germany AP Germany reacts to Cologne New Year's Eve attacks German far-right supporters demonstrate at Cologne`s train station (Reuters) Reuters Germany reacts to Cologne New Year's Eve attacks Supporters of anti-immigration right-wing movement Pegida in Cologne, Germany, January 9, 2016. Reuters Germany reacts to Cologne New Year's Eve attacks Police used pepper spray to control supporters of Pegida, Hogesa (Hooligans against Salafists) and other right-wing populist groups as they protested against the New Year's Eve sex attacks on 9 January, 2016 in Cologne, Germany Reuters Germany reacts to Cologne New Year's Eve attacks Police use a water cannon during a protest march by supporters of anti-immigration right-wing movement Pegida in Cologne, Germany, January 9, 2016 Reuters Germany reacts to Cologne New Year's Eve attacks Police use pepper spray against supporters of anti-immigration right-wing movement Pegida, in Cologne, Germany, January 9, 2016. Reuters Germany reacts to Cologne New Year's Eve attacks Artist Mira Moiré protests naked in Cologne against the mass sex attacks on New Year's Eve AP Germany reacts to Cologne New Year's Eve attacks A demonstrator holds a sign in German that reads 'No violence against women' during a demonstration in the wake of the sexual assaults on New Year's Eve, outside the cathedeal in Cologne, Germany, 09 January 2016. EPA Germany reacts to Cologne New Year's Eve attacks Counter demonstrators hold up a sign reading "Against sexism, against racism" as they protest against a demonstration of the islamophobic movement PEGIDA at the train station in Cologne, Germany, on January 9, 2016. AFP/Getty Images Germany reacts to Cologne New Year's Eve attacks Demonstration by a women’s group on Saturday (AP) AP

The three men who have been arrested are asylum seekers from Pakistan. All have been charged with sexual assault charges.

Police have said the number of complaints could rise and are hunting for between two and three more men.

Cologne victims speak

The attacks are similar to those which occured on New Year's Eve in Cologne and other German cities.

Many of the perpetrators were allegedly of North African or Arab descent and the assaults sparked a backlash against refugees throughout Europe.