More than 60 people were killed when a block of flats weakened by the weight of two extra illegal storeys collapsed in India.

Around another 70 were injured after the crude brick building crashed down in a congested New Delhi district the previous night.

The landlord has fled and is being hunted by police.

Rescue workers continued to tear through the pile of broken bricks, twisted iron rods and concrete slabs yesterday, but hope for finding more survivors was fading.

It was mostly occupied by poor migrant workers and their families, because it was one of the rare homes they could afford amid the skyrocketing property prices in the crowded city.

The building was two floors higher than legally allowed, and its foundation appeared to have been weakened by water damage following monsoon rains.

Poor building materials and inadequate foundations are often blamed for building collapses in India. In New Delhi, where land is at a premium, unscrupulous builders often break building laws to add additional floors to existing structures.

While the collapse was still being investigated, New Delhi’s top elected official blamed poor construction and maintenance and vowed to punish those who had allowed the extra floors to be built.

“The scale of the tragedy is unprecedented,” Sheila Dikshit said.

Another building next door was evacuated after its basement was also discovered flooded.

When the building fell, those living nearby said they heard a rumble like thunder. They sprinted to the site and tried to reach trapped survivors by digging with their hands into the piles of concrete, bricks and mortar before police and rescue teams arrived.

“There were so many dead bodies, there was no movement at all,” said Dil Nawaz Ahmed, a 25-year-old journalist who lives nearby. He said he managed to help free five injured residents, but mainly pulled out bodies, which he carried to waiting ambulances. “There were many women and children.”