BERLIN — The German mass-circulation daily Bild has “emphatically” apologized to its readers for an article that said a “mob” of Arab men had sexually assaulted women on New Year’s Eve in a Frankfurt restaurant, after the police said that an investigation had failed to turn up any evidence.

The accusations carried echoes of genuine attacks on New Year’s Eve a year earlier, and Nadja Niesen, a spokeswoman for prosecutors in Frankfurt, said on Thursday that the authorities had opened a preliminary investigation of two people suspected of fabricating a crime.

In its Feb. 6 report, Bild, the most widely read newspaper in Germany, quoted Jan Mai, the owner of a cafe in downtown Frankfurt, as saying that 50 “Arab-looking men” had assaulted women on Dec. 31. It also quoted a woman it identified only as Irina A., 27, who said she had been among those who were groped “everywhere” by the men.

The article mirrored a high-profile episode in Cologne a year earlier, when hundreds of women reported being robbed or sexually attacked on New Year’s Eve, some by groups of migrants and newly arrived asylum seekers.