The University of Nebraska-Lincoln is extending its mask mandate as virus cases soar across the state, and all returning students and faculty will be required to take a COVID-19 test at the start of the spring semester. Masks will be required indoors throughout the university’s campuses, including at sporting events. Separately, Omaha police and fire officials announced Wednesday that they will require masks after a virus outbreak among their departments. The seven-day rolling average of daily new cases in Nebraska has more than doubled over the past two weeks from 744.29 new cases per day on Dec. 20 to 1,734.86 new cases per day on Monday.