Video footage shared on social media shows passengers panicking before being crushed at the bottom of the escalator as the stairs crumpled.
Three people are in a serious condition following the horrific incident, including a man who reportedly lost part of his foot.
Many of the victims were Russian football fans heading to a Champions League match between AS Roma and CSKA Moscow, a spokesperson from Italy’s Fire Brigade said.
Local authorities said the victims were transported to five hospitals across Rome.
Repubblica metro station, which lies under Piazza della Repubblica, was closed following the incident and remains closed for further investigation.
Rome’s Public Prosecutor’s Office has opened a probe into the cause of the accident, while the capital’s public transport company, ATAC, has also opened an internal investigation.
ATAC has claimed the escalator underwent regular maintenance checks and the results were “in accordance to the norms”.
Italian media reported that the escalator collapsed after singing and chanting fans began jumping up and down on it.
Deputy Prime Minister Matteo Salvini declared the incident was caused by “dozens of drunkards making a big mess”.
Those involved in the accident fired back saying that while there was singing, nobody was jumping.
Russian victims are reportedly planning to sue the Roman authorities over the episode.
The club’s official fansite, Red-Blue World, has asked for victims to send in information about the incident so that an official lawsuit can be filed.
