The chief minister gave the warning after he chaired a Covid Task force meeting.
In a statement issued after the meeting, Thackeray said in the last one-and-a-half month, Covid cases in the state had increased seven-fold.
Additional chief secretary (health) Pradeep Vyas said Mumbai, Thane and Pune had around 97% of the state’s cases.
The chief minister said all experts had predicted that cases could rise further and hence the state would keep a watch on the situation for 15 days, hinting that if Covid cases continued to rise, then there might be some restrictions after 15 days.
“If people don’t want restrictions, then they should have their own practice discipline. Wear masks, get vaccinated, follow Covid-appropriate behaviour,” he said.
The number of cases has been rising since March, when Mumbai reported fewer than 70 cases a day.
Several ministers including deputy chief minister Ajit Pawar have also been advocating the need for people to wear masks.
“The rising Covid cases is a bit worrisome. Everyone should be wearing masks. The cases are still low, however we have seen how it goes out of control,” Pawar said on Thursday.