At least 40 people are believed to have died after a building collapsed in on itself, near the Indian city of Mumbai. Police reports say the construction was an illegally built seven-storey block in Thane, a suburb of one of the country's most populous metropolitan areas.

According to the BBC, not only was the structure built without permission from the relevant authorities, it was being lived-in despite the fact heavy construction work was still being undertaken.

"The building (that has collapsed) was an unauthorised construction. We are going to investigate thoroughly into this and prepare a report," Sandeep Malwi, a spokesman for the Thane municipal corporation, was quoted by NDTV. City officials say the building was built on forest land and as many as 35 families were living in the structure.

A local newspaper, the Hindustan Times, reported that at least 60 people had been injured and the death and injury tolls were expected to rise. Worse still, at least 10 of the deceased are believed to be children and one of the deceased has been identified as Shakila Imran Siddiqui, a pregnant woman.

The police have registered a case against the builders under Section 304 of the Indian Penal Code, which is culpable homicide not amounting to murder. The Hindustan Times report identifies the builders as Salil and Khalil Jamadar but there is some confusion on that front because a report by NDTV claims the names to be Jamil Qureshi and Salim Shaikh. In either case, though, the two builders have been absconding since the incident.

The injured have been admitted to various local hospitals and the NDTV report states the chief minister of the state of Maharashtra has visited the scene of the accident.

It is understood that substandard building material may have contributed to the accident; a rapidly exploding population and unregistered builders looking to increase profits by cutting corners on safety are a common feature in most Indian cities.

This is the third instance of a building collapsing, in Maharashtra alone, over the past few months. The two earlier occasions were in September and December and a combined 20 people lost their lives in those incidents.

Check out photographs of the collapsed building in Thane, India...

Rescue workers use a cutting tool to search for survivors after a residential building collapsed in Thane, on the outskirts of Mumbai April 4, 2013. At least nine people died and over 40 people were injured when an under-construction residential building collapsed on Thursday evening, local media reported.Reuters
Rescue workers search for survivors at the site of a collapsed residential building in Thane, on the outskirts of Mumbai April 4, 2013. At least nine people died and over 40 people were injured when an under-construction residential building collapsed on Thursday evening, local media reported.Reuters
Rescue workers carry a woman who survived from a collapsed residential building in Thane, on the outskirts of Mumbai April 4, 2013. At least nine people died and over 40 people got injured when an under-construction residential building collapsed on Thursday evening, local media reported.Reuters
Rescue workers carry a body from a collapsed residential building in Thane, on the outskirts of Mumbai April 4, 2013. At least nine people died and over 40 people were injured when an under-construction residential building collapsed on Thursday evening, local media reported.Reuters
Rescue workers search for survivors at the site of a collapsed residential building in Thane, on the outskirts of Mumbai April 4, 2013. At least nine people died and over 40 people were injured when an under-construction residential building collapsed on Thursday evening, local media reported.Reuters