HOUSTON (KIAH) — Due to the rising number of COVID-19 cases across the Houston area, several school districts are either facing a staffing crisis or closing schools for the weekend.

In Conroe, almost 900 Conroe ISD employees have called in sick on Thursday, and only 500 substitute teachers are available to work on Friday, CISD Superintendent Dr. Curtis Null said on a live video on Thursday.

Null said that the spike in COVID cases has hit district employees the hardest, with more employees with positive COVID cases now than it was in the beginning of the school year. The district reports 368 employees with active cases on Friday, with 115 of them coming this week.

Because of the rise of cases, CISD will limit visitors and guests at all of its schools, as well as limit large gatherings and unnecessary travel.

Meanwhile, Sealy ISD will remain closed on Friday and on Tuesday, Jan. 18.

Monday was already a scheduled holiday, in observance of Martin Luther King Jr. Day.

The district has recorded more 140 COVID cases since school returned from holiday break on Jan. 3.

Sealy is the first school district in the Houston area to close its schools this year due to rising COVID cases.