At least 70 people were feared trapped after a five-storey apartment building collapsed late Monday in western India, police said.

The building comprised 47 flats, police in the town of Mahad -- 120 kilometres (75 miles) south of Mumbai -- said in a statement.

The cause of the accident was not clear but building collapses are common during India's June-September monsoon, with rickety structures buckling under the weight of non-stop rain.

"Fifteen injured people have been rescued and taken to hospital," Mahad police said.

Rescue teams and canine squads were deployed to the scene of the accident, a statement from India's National Disaster Response Force said.

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.