The Thane Municipal Corporation (TMC) and traffic police have separately issued notices to 16 Durga puja mandals in the city for alleged irregularities.
According to a deputy municipal commissioner (DMC), some 124 mandals were issued permission for the puja.
The 16 mandals, which have been served notices by the TMC, are from the Uthalsar, Naupda and Vartak Nagar ward committees, he said.
"Of these, we found that there were irregularities in nine mandals. These irregularities ranged from various issues like lack of necessary permission, encroachment on roads and so on," he said, "We have issued them show cause notices and have asked them to rectify the irregularities."
Other mandals had not taken necessary permission for construction of pandals or had failed to procure the no objection certificate from traffic police and local police stations, he said, adding that a showcause notice has been issued to them and they have been asked to furnish the details to the TMC.