An alleged serial rapist who was accused by dozens of anonymous girls of sexually harassing, assaulting, raping or blackmailing them has been arrested, the Egyptian prosecution said on Saturday.

The young man, Ahmed Bassam Zaki, will now be investigated, the prosecution said in a statement.

Earlier in the day, a security source demanded that the girls who were subjected to any kind of sexual violence at the suspect's hands file formal complaints so he can be prosecuted.

On Friday, Egypt's prosecution said it had received one official complaint "made online on 3 July from a girl who said the young man threatened her in November 2016 to have sex with her."

Accounts from girls who said they had been sexually assaulted by Zaki went viral on Twitter and Instagram in the past few days, leading to calls for his arrest. The girls, who reportedly included minors, were not identified.   

Soon after, an Instagram account was created under the name "@assaultpolice", calling on women to share their horrific stories. Within the next 24 hours, the account received more than 150 messages, including some that contained screenshots of messages and recordings of calls with Zaki.