The two-storey structure at Gaibi Nagar under Shanti Nagar police station limits in the town crashed at around 9.30 AM, Bhiwandi tehsildar Vaishali Lambate said.
About 7-8 families were residing in the building.
Firemen and policemen rushed to the site. It was not known immediately known if people were still trapped in the debris, police said.
A spokesman of Thane district disaster cell said that at least five persons were killed and ten others injured, including one seriously, in the building collapse.
Nine of the injured were rushed to Thane Civil Hospital where they were being treated for their injuries, he said, adding that one person has been admitted to a hospital in Bhiwandi.
District Collector Dr Mahendra Kalyankar rushed to the site to supervise the relief and rescue operation.
Heavy rains were affecting the rescue operation, officials said.
It was yet to be ascertained whether the structure was in the list of dangerous buildings, sources said.
Following the heavy rainfall since early this morning, many low lying areas were waterlogged in Thane city and surrounding areas.
Thane Municipal Commissioner Sanjeev Jaiswal, after visiting the disaster control cell, issued a warning to residents of the city not to step out of their houses unless it was absolutely essential.