The city of Denver on Monday warned that another stay-at-home order could be issued because of the rising number of COVID-19 cases.

“What we are doing isn’t working,” the city said in a tweet. “We can do better. Wear a mask, maintain social distancing and wash your hands.”

Colorado’s seven-day, moving average positivity rate is at 6.4% — above the state’s preferred 5% threshold.

The positivity rate is the number of tests that come back with a COVID-19 result. The World Health Organization recommended in May that the positivity rate should be below 5% to contain the virus.

Gov. Jared Polis has urged residents to be more vigilant. He extended a statewide mask mandate two weeks ago, but positive cases continue to increase.

Denver Mayor Michael Hancock earlier this month implemented stricter mask and gathering requirements last week.

Face coverings in the city are required if people are outdoors and congregating with people outside of immediate household members.

Also, gatherings are restricted to only five people. There are exceptions for people participating in organized sports, activities, learning environments and businesses that are following separate guidelines approved by the state.