O'FALLON, Mo. (AP) — Missouri's health department on Friday cited 31 additional coronavirus deaths, the worst one-day increase since the pandemic began.

The website for the Missouri Department of Health and Senior Services showed 738 deaths, up from 707 on Thursday. The previous one-day high for deaths was 29 reported on April 25. The website also showed an increase of 122 new cases, bringing the total to 12,795.

Email messages seeking comment from the health department were not immediately returned.

Republican Gov. Mike Parson allowed the state to reopen May 5, though still requiring 6-foot social distancing and, for many businesses and organizations, capacity limits indoors. On Thursday, he announced that the second phase of the plan was pushed back to June 15 from May 31.

Parson said the change was not due to a setback but out of an abundance of caution.

“We just need to be a little careful here for a little while,” Parson said at a news conference in St. Louis County.

Still, the decision followed two alarming instances that drew national attention: The emergence of photos and video showing large groups of mostly young people crowded together at Lake of the Ozarks swimming pools over the Memorial Day weekend, and the report that up to 140 clients at a Springfield Great Clips were potentially exposed by two workers who tested positive for COVID-19, the illness caused by the coronavirus.

The Springfield-Greene County Health Department is testing all of the exposed Great Clips clients, and test results for the first 42 were negative, director Clay Goddard said. It wasn’t immediately clear when the remaining results would be available.

The health department announced last week that a stylist served 84 clients over eight days in mid-May while experiencing coronavirus symptoms. A co-worker also became sick and potentially exposed 56 more. The health agency said both stylists tested positive for COVID-19.

The stylists and all of their clients wore face masks, health officials said. Goddard said the negative tests so far may be evidence of the value of facial coverings.

Parson said he’s hopeful Missouri will see “more consistent policies” across the state by the middle of June, when phase 2 of his reopening plan is expected to begin. He has not yet announced how phase 2 will differ from phase 1.