He drew parallels with the 1984 Games in Los Angeles in which there were concerns "about how many Olympic athletes were going to die because of the smog," and a Zika virus outbreak prior to the 2016 Games in Rio de Janeiro.
At least two people were wounded when the subway car they were riding in was apparently caught in the crossfire during the operation, news site G1 reported.
Experts believe human activity, such as widespread deforestation, destruction of animals' habitats and climate change, is spurring this increase, and warn more pandemics could occur if nothing is done.
The city of 6.7 million people will impose a curfew from 11 p.m. to 5 a.m. and order restaurants to close at 5 p.m., while certain businesses, such as clubs, will be shut altogether.
While COVID-19 deaths and infections are falling globally, that is not the case in Brazil, where a record 1,910 people died from the virus on Wednesday.
The federally-funded Fiocruz biomedical center in Rio de Janeiro is still awaiting its first shipment of ingredients for AstraZeneca's vaccine, pending Chinese export approval.
Football superstar Neymar meanwhile tried to douse a firestorm of controversy over reports he organized a week-long party for 500 revelers at his mansion outside Rio.