A Kentucky school district canceled classes after several children and staff members tested positive for COVID-19 as the highly contagious delta variant causes a statewide surge of new infections.

Lee County public schools will be closed for three days through Wednesday to allow time for coronavirus test results and to enable some staff members who went into quarantine last week to possibly return to school Thursday, Superintendent Sarah Wasson said on social media.

“This will be a tough year and we don’t want to have to shut down this early, but if we can determine who is positive now we believe we can stay in school longer,” she said Sunday.

One child in kindergarten, one first-grader and one fourth-grader tested positive, Wasson said. Students within 6 feet (2 meters) of the infected children for more than 15 minutes were asked to quarantine, she said. Five staff members also tested positive, she said.

“While this is not a huge number, the number of staff that have had to quarantine or are not feeling well and will be tested tomorrow is above 17 at the elementary school alone,” she said.

The eastern Kentucky district began the fall semester last Tuesday. Later that day, Kentucky Gov. Andy Beshear required mask-wearing in K-12 schools statewide as the fast-spreading delta variant causes waves of new coronavirus cases and hospitalizations.

On the first day of classes, Lee County schools required masks on school buses and “highly recommended” that all students and staff wear masks in schools. The district promptly complied with the Democratic governor’s mask mandate starting the next day.

Beshear pointed to the school closure in a Monday tweet, saying: “Getting vaccinated and wearing a mask is how our kids stay in school. Let’s put their education first and do the right thing.”

Without masks, children not old enough to receive the coronavirus vaccine would be defenseless against the virus, the governor said last week. The number of children infected with the virus has risen sharply amid the delta variant outbreak. Children under age 12 are not eligible for the shots.

Republican Attorney General Daniel Cameron last week called the mask order an “unlawful exercise of power” and challenged the governor’s action in the Kentucky Supreme Court. The state’s high court also is reviewing new GOP-backed laws meant to rein in the governor’s executive powers.