Jakarta: A mezzanine floor inside the Indonesia Stock Exchange tower has collapsed, injuring more than 70 people and forcing a chaotic evacuation.

A video posted on Twitter by ABC Indonesia Correspondent Adam Harvey showed what he said was a group of school students on the floor as it gave way.

Jakarta police spokesman Argo Yuwono said hundreds of students were visiting the stock exchange at the time of the collapse.

The incident happened at noon when workers were on a lunch break.