photo by: Associated Press

Dr. Lee Norman, Kansas secretary of health and environment, answers questions about the coronavirus pandemic as Gov. Laura Kelly watches during a news conference, Monday, March 23, 2020, at the Statehouse in Topeka, Kan. (AP Photo/John Hanna)

Story updated at 6:46 p.m. Monday

TOPEKA — Shelter-in-place orders are about to take effect for about a third of Kansas’ population to slow the spread of coronavirus, and Gov. Laura Kelly announced Monday that she will tighten restrictions on public gatherings.

Five counties with about 1 million of the state’s 2.9 million residents were telling residents to stay home starting Tuesday, except for essential business, such as buying food or seeking medical care. They include Johnson County, the state’s most populous county; three other neighboring counties in or touching the Kansas City area, and Douglas County, home to the main University of Kansas campus.

Kelly also said she would issue an executive order Tuesday to ban public gatherings of more than 10 people. Kelly last week banned gatherings of more than 50 people.

The governor also issued an executive order Monday to postpone the state’s income tax filing deadline from April 15 to July 15, in line with a change in the federal filing deadline. She also granted a two-month extension to driver’s licenses that expired after March 12 because driver’s license offices are closed.

“Confirmed, positive cases are expected to tick upward at a rapid pace over the next 10 days,” Kelly said during a Statehouse news conference. “The crisis continues to evolve by the hour.”

Kelly said she is not yet issuing a statewide shelter-in-place order as governors have done in some other states, including California, Illinois, Massachusetts, Michigan and New York, because 89 of Kansas’ 105 counties had yet to see a confirmed coronavirus case as of Monday morning. But she warned that such an order could become “unavoidable in the coming days.”

And the Sedgwick County Commission voted 3-2 on Monday to recommend a stay-at-home order, with the county health officer making the final decision. Sedgwick County, home to the state’s largest city of Wichita, has more than 510,000 residents, so if it told residents to stay at home, more than half of Kansas’ population would be under such an order.

Kansas has confirmed almost 80 cases of COVID-19, the disease caused by the coronavirus. That’s an increase of at least 15 since Sunday. It has had two COVID-19-related deaths, one in Johnson County and the other in neighboring Wyandotte County in the Kansas City area.

For most people, the coronavirus causes only mild or moderate symptoms, such as fever and cough. But for some, especially older adults and people with existing health problems, it can cause more severe illness.

Dr. Lee Norman, the state’s health secretary, said he expects Kansas to have between 300 and 400 confirmed cases by the end of March.

Norman said Friday that the state was close to running out of testing kits, which would force it to rely on private labs for testing. But he said the state obtained enough kits Saturday to test 700 patients, which should last into next week.

Besides Johnson County and Douglas County, which is home to the college town of Lawrence, shelter-in-place orders also take effect Tuesday in Wyandotte and Leavenworth counties in the Kansas City area, and Miami County to the south, where many residents work in Johnson County. All five orders will remain in effect until April 23.

A sixth county, Doniphan County in the state’s northeast corner, also was imposing a stay-at-home order starting Thursday and lasting through April 6.