At least 23 people including children are now dead after an overpass carrying a subway train collapsed in Mexico City late Monday night.

And according to officials at least 70 people, children included have been hospitalised, some in serious condition.

Reports are that the train was traveling on an elevated part of the city’s rapid transit system on the newest Line 12, also known as the Golden Line, when part of the overpass collapsed onto traffic below.

The accident happened as the metro train was traveling between Olivos and Tezonco Metro stations.

According to Mexico City’s Interior Minister Alfonso Suarez Del Real the accident happened at 10:25 p.m. local time.

The Metro’s Line 12, where the accident happened, was opened in 2012. Mexico City Mayor, Claudia Sheinbaum said there would be an investigation into the accident

“Our main task is to attend to the people who are in the hospitals, to attend to the relatives of the victims who unfortunately died in this incident,” she told Reuters.

“The Public Prosecutor’s Office will carry out all the investigations, will make all the expert reports to find out what happened in this accident on line 12 of the subway,” she added.