An injured woman lays inside an ambulance outside the stock exchange building in Jakarta, capital of Indonesia, Jan. 15, 2018. Part of the building's first floor collapsed on Monday, injuring several people. (Xinhua/Sudiro)

JAKARTA, Jan. 15 (Xinhua) -- Indonesian police have undertaken investigation after a floor at the country's stock market building collapsed that injured dozens of people, a police officer said on Monday.

National police spokesman Inspector General Setyo Wasisto disclosed that police investigators would investigate blueprint of the building after the incident.

"Every building has its own blueprint, so there must be information stipulating how long a building will remain strong," he said at the police headquarters.

The spokesman ensured that the cause of the incident is not an explosion.

The country's financial services authority also supported the investigation, said head of international division of the authority Anto Prabowo.