Indian rescue workers have pulled out eight bodies from the wreckage of a three-storey building in the northern city of Lucknow, reports said, with the state chief minister calling the deaths “heart breaking”.

The Press Trust of India (PTI) news agency broadcast images of piles of concrete, and state rescue teams with heavy digging machines searching for bodies on Sunday.

PTI quoted officials as saying eight bodies had been pulled out, and 28 people were injured.

Yogi Adityanath, the chief minister of Uttar Pradesh state where Lucknow is located, called the deaths “heart breaking” in a statement, and offered his condolences to the grieving families of the dead.

The commercial building, which had been used by multiple small companies, including as a warehouse and as a vehicle workshop, collapsed on Saturday afternoon.

It was not clear if there were others still trapped.

The cause of the collapse was not immediately established.

But Akash Singh, who worked in the building, said a pillar had developed a crack.

He had moved to the ground floor fearful it would worsen, with lashing monsoon rains battering the city.

“Suddenly, the entire building collapsed on us,” Singh was quoted as saying by PTI.

The Times of India newspaper quoted witnesses as saying that in recent days two trucks collided with the building while unloading goods, possibly triggering the collapse.

Police also reported that the building, constructed about four years ago, was undergoing some construction work at the time of the collapse, according to the Hindustan Times.

Building and construction accidents are common during India’s June-September monsoon season, with old and rickety structures buckling under days of nonstop rain.