The mass attacks on women in Cologne and other German cities on New Year's Eve have prompted more than 500 criminal complaints, with Cologne investigations focused largely on asylum seekers or illegal migrants from north Africa, police have said.The attacks, mostly targeting women and ranging from theft to sexual molestation, have prompted a highly-charged debate in Germany about its open-door policy to migrants and refugees, more than one million of whom came to the country last year.In Cologne, police said that 379 criminal complaints had been filed by individuals or groups, while police in Hamburg said 133 similar complaints had been lodged in the north German city. Frankfurt also registered complaints, although far fewer. The Cologne attacks also heated up debates on immigration in neighboring Austria and Switzerland."What happened in Cologne is unbelievable and unacceptable," Austrian Interior Minister Johanna Mikl-Leitner, a member of the conservative People's Party that is junior coalition partner to the Social Democrats, told newspaper Oesterreich.There had been a handful of similar incidents in the border city of Salzburg. "Such offenders should be deported," she said, backing a similar suggestion by German chancellor Angela Merkel.