A crane at a construction site in downtown Bangkok collapsed on Wednesday, injuring 10 students.

The crane reportedly crashed into a building of Assumption Convent School in Bangkok's Bang Rak district while students were in class.

Seven students were rushed to Lertsin Hospital while three others were sent to Saint Louis Hospital, said Phonthep Sae-Heng, chief of the city's Erawan medical emergency center.

Director of Lertsin Hospital Dr. Sompong Tanjariyaporn said that one student, hit in the head, was unconscious but has already regained consciousness and put under medical surveillance.

Local media reported that Bang Rak district has cordoned off the crane collapse site, which was found being modified without permission.

The crane was used to construct an addition of a condominium building and the crane could not bear excessive weight and fell onto the ground.

Earlier, construction materials from the site fell onto the school and nearby houses many times.

The authorities announced the area off-limits until the building owner seeks permission for the building modification legally.