PHOENIX (AP) — With Arizona hospitals admitting increasing numbers of COVID-19 patients, state health officials said Wednesday that they suspended some transfers of patients from other states.

Out-of-state hospitals can still transfer patients to Arizona through direct hospital-to-hospital requests, but the use of the interstate Arizona Surge Line system was suspended Monday, Department of Health Services spokeswoman Holly Poynter said.

The system was activated April 21 to expedite transfers of virus patients for higher levels of care, to efficiently use hospital beds and to equalize patient numbers among hospitals, according to the department.

Poynter said the Surge Line service for out-of-state patients will resume after hospital occupancy drops again.

The suspension was first reported Tuesday night by the Arizona Republic.

The department says virus-related hospitalizations had reached 2,217 as of Tuesday, including 531 people in intensive care units. Arizona had about 500 virus patients most days during September before the outbreak worsened in October.

Including all types of patients, ICU beds reached 90% occupancy last weekend and remained at that level Tuesday, according to the department.

While some Arizona hospitals have been treating patients transferred from other states during the pandemic, some Arizona patients have been transferred to hospitals in neighboring states, including Nevada and New Mexico.

Citing a growing patient load at the hospital in Safford, the Board of Supervisors in conservative Graham County, near the New Mexico border, reluctantly adopted a mask mandate Monday morning. Over the summer, the county and the cities of Safford, Thatcher and Pima strongly recommended mask-wearing in public but did not require it.

The Graham County mask order lasts for six weeks. Violators will be warned on a first offense and face a fine of up to $50 if they dodging the mandate.

Arizona on Wednesday reported 3,982 additional known COVID-19 cases, with nine more deaths, increasing the state's totals to 310,850 cases and 6,524 deaths.

Seven-day rolling averages of new cases, daily deaths and COVID-19 positive tests all increased in the past two weeks, according to data from the COVID Tracking Project and Johns Hopkins University

The number of infections is thought to be far higher than reported because many people have not been tested, and studies suggest people can be infected with the virus without feeling sick.

For most people, the new coronavirus causes mild or moderate symptoms, such as fever and cough that clear up in two to three weeks. For some, especially older adults and people with existing health problems, it can cause more severe illness, including pneumonia, and death.