FLAGSTAFF, Ariz. (AP) — The Navajo Nation has extended its weekend lockdowns preventing people from leaving their homes, except in emergencies, on the vast expanse of land that has been harder hit by the cornavirus than any other Native American reservation in the U.S.

The tribe first put in place the 8 p.m. Friday to 5 a.m. Monday lockdown last weekend for the reservation that lies in parts of Arizona, New Mexico and Utah and is larger than the state of West Virginia. It came after a nightly curfew was imposed to keep people at home from dusk to dawn during the week.

Two employees with the Navajo Nation Police Department have tested positive for COVID-19, the department said Tuesday.

“It’s up to us, ladies and gentlemen, stay home and abide by these so we don’t have high numbers,” Navajo President Jonathan Nez said in a town hall announcing that the weekend lockdowns would continue. “Tell each other that.”

The announcement came as the number of coronavirus cases on the Navajo reservation rose to 838 with 33 deaths. About 175,000 people live on the Navajo Nation and Nez said he was working to ensure non-essential business would close as ordered.

Tribal police enforced the weekend lockdown by setting up checkpoints in Navajo communities. They issued more than 100 criminal nuisance citations for violating it on Friday and Saturday, Navajo Nation police spokeswoman Christina Tsosie said Wednesday.

Enforcement of the lockdown over Easter weekend was the largest coordinated effort ever for the department, said Navajo Police Chief Phillip Francisco said.

“We're asking everyone to comply so we don't have to write any tickets,” he said.

The citations carry possible fines of up to $1,000 and 30 days in jail. The lockdowns and curfews apply to tribal and non-tribal members, including those who live or operate businesses on sections of non-reservation land within the boundaries of the Navajo Nation.

Essential employees, such as health care workers, law enforcement and emergency responders, are exempt from the restrictions but must be able to provide official identification and a letter from their employers.

For most people, the 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.

Nez said the number of COVID-19 cases is expected to increase as the tribe receives test kits that will more quickly deliver results.

Among those infected on the reservation are six people who work for the police department, Tsosie said.