Police in southern India detained five construction company officials Sunday, after two building collapses killed at least 22 people, emboldening demands for stronger regulation of the nation’s construction sector.

Nearly 90 contract workers were believed to have been in the basement of the 11-story structure to collect their wages when it collapsed Saturday amid monsoon rains in the outskirts of Chennai, the capital of Tamil Nadu state.

Rescuers using gas cutters and shovels found 31 victims of the collapse so far, according to the police. Four died on the spot and another seven succumbed to their injuries at a nearby hospital. Another 20 people were found to be injured so far.

The exact number of those trapped remains unknown but rescuers could hear feeble voices in the debris, disaster management officials said.

In a separate collapse earlier Saturday, 11 people died and one survivor was being treated in a hospital after a four-story, 50-year-old structure toppled in a low-income area of New Delhi, said fire service officer Praveer Haldiar.

Most homes in that part of the capital were built without permission and using substandard materials, police officer Madhur Verma said.

Building collapses are common in India, where high demand for housing and lax regulations have encouraged some builders to cut corners, use substandard materials or add unauthorized extra floors.

Numerous building accidents in India's large cities have killed about 100 people in the past year, according to local media reports. More than 50 people were killed when an apartment block collapsed in Mumbai last September.

Saturday’s collapses appear to have sparked an outcry for public safety reform and better law enforcement.

"Building collapse in Delhi brings forth need to adhere to safety requirements," Vijay Goel, a lawmaker from the ruling Bharatiya Janata Party that controls the Municipal Corporation of Delhi, said on Twitter.

Wire services