At least 90 people were feared trapped after a five-story apartment building collapsed late Monday in India's western state of Maharashtra, police said.

The residential building said to house about 45 families fell down in the Raigad district in the town of Mahad – 120 kilometres (75 miles) south of Mumbai – on Monday evening, regional police head Anil Paraskar said.

"At least 22 injured people have been rescued and taken to hospital," Paraskar said by phone from the site.

It was not clear what caused the building to collapse and an inquiry had been launched, Paraskar said.

Three teams of the National Disaster Response Force and canine squads had been rushed to the accident site and will carry out rescue operations through the night along with the police and fire services, he added.

Building collapses are common during India's June-September monsoon, with rickety structures buckling under the weight of nonstop rain.

The monsoon plays a vital role in boosting agricultural harvests across South Asia. But it also causes widespread death and destruction, unleashing floods, triggering building collapses and inundating low-lying villages.

The death toll from monsoon-related disasters this year has topped 1,200, including more than 800 lives lost in India alone.