An illegally built housing block in India collapsed on Thursday killing at least 35 people including 11 children.

The building in Thane, near the city of Mumbai, was partially occupied despite not being fully constructed.

More than 20 people are reported still missing.

Indian police said the building was an illegal construction, a common occurrence in the country leading to poor quality and unsafe builds.

india building collapse

Rescue teams equipped with six bulldozers search the site

Local police commissioner, KP Raghuvanshi, said: "There may be [a] possibility people have been trapped inside right now."

A rescue worker added: "All the three floors are sandwiched … so it is very difficult for us," reports the Guardian.

Most of the dead are construction workers who were staying in the building as it was built.

A witness to the collapse told the BBC: "The building collapsed like a pack of cards within three to four seconds."