Seven labourers were killed and one was seriously injured after falling to the ground while working inside an elevator shaft at an under-construction building in Ahmedabad city on Wednesday morning, police said, reports PTI.

Police had earlier put the death toll at eight, but an official later said one worker was undergoing treatment.

The incident took place around 9:30 am at the site located near Gujarat University. A senior police official had initially said the elevator carrying the workers had crashed to the ground from the seventh floor, but later police said the workers fell when the structure inside the elevator shaft gave way. "Six labourers who were working inside the elevator shaft on the 13th floor fell to the ground after the support structure suddenly collapsed," said Assistant Commissioner of Police L B Zala.

"Two others who were working on the fifth floor also fell down after losing balance. Seven of them died while one is undergoing treatment," he added.

Preliminary probe revealed that necessary safety measures were not in place and appropriate action will be taken if any negligence is found on the part of the contractor, the ACP said.

An eye-witness who was working on the ground floor told reporters that the victim labourers were natives of Panchmahal district.

They were not wearing any safety gear, he said. Chief Fire Officer of Ahmedabad, Jayesh Khadia expressed surprise that the fire department did not receive any call after the incident.

"We have not received any calls. We learnt about the incident from the media. Our primary analysis suggests that the structure on which these labourers were standing inside the elevator shaft collapsed due to unknown reasons," he said.

Ahmedabad Mayor Kirit Parmar said police will take necessary action against the builders if they are found to have violated any laws.

"The builders had taken necessary permissions from the Municipal Corporation to construct the building. But though the incident took place around 9:30 am, our officials were informed around 11:30 am," said Parmar.