The cable bridge that collapsed in the western Indian state of Gujarat on Sunday evening, claiming some 91 lives, reopened barely four days ago "but without the mandatory fitness certificate".

The tragedy occurred in Morbi district of Gujarat, the home state of Indian Prime Minister Narendra Modi, around 6.45pm. Over 500 people had thronged the bridge to perform religious rituals at the time.

A senior civic body official told the local media that the colonial-era suspension bridge was closed for over six months for repairs and reopened to the public only on October 26.

Read: 91 killed in India bridge collapse

"It was opened to the public after the completion of the renovation work. But the local municipality had not yet issued any fitness certificate," chief officer of Morbi Municipality Sandeepsinh Zala said.

The state government was quick to accept responsibility for the tragedy and announce a five-member probe panel.

"Renovation happened last week. We are also shocked (at the tragedy). The state government takes responsibility for this tragedy," Brijesh Merja, a Gujarat minister, told the media.