COVID-19 cases are back on the rise in New York City and around the country.

The New York City Health Department sent a tweet Sunday, saying that the city was seeing high levels of COVID-19 and recommend that New Yorkers wear a mask in all public indoor settings and around crowds outside.

City data shows there has been a daily average of more than 3,000 new cases across the city over the last seven days.

The Bronx has the third-highest positivity rate percentage of the five boroughs, behind Queens and Staten Island. Brooklyn has the lowest.

Some health experts have warned that these numbers might be even higher because so many people are doing at-home COVID-19 tests rather than at a hospital or testing site.

The Centers for Disease Control and Prevention says that two subvariants of Omicron -- BA.4 and BA.5 -- are responsible for around 70% of new infections.

Health experts also say it is possible that these subvariants are sometimes getting past the immunity built up from a previous COVID case or from vaccination.

Data shows the vaccine does still protect you from severe illness or death, and unvaccinated New Yorkers still make up the most cases, hospitalizations and deaths.

At this time, the city has not put the previous indoor mask mandates or proof of vaccination requirements back in place despite these new numbers.