Germany's ruling parties promised on Friday to crack down aggressively on migrants who commit crimes, after assaults on women in Cologne on New Year's Eve stoked debate about Chancellor Angela Merkel's welcoming policy towards refugees, according to Reuters. Some 121 women are reported to have been robbed, threatened or sexually molested there by gangs of mostly drunk men between 18 and 35 years old while out celebrating. Cologne's police chief has said the perpetrators appeared to be of "Arab or North African" origin and the head of the police union in the region was quoted by German daily Die Welt as saying there were "definitely" refugees among them. In response to the assaults, Merkel's Christian Democrats (CDU) have called for tougher penalties against offending asylum seekers, according to a draft paper seen by Reuters ahead of a meeting of the party leadership in Mainz. The paper says refugees and asylum seekers who have been sentenced to prison or probation should be barred from eligibility for asylum.