Staff members at the U.S. Embassy in Afghanistan are on lockdown after an outbreak of coronavirus cases, U.S. officials said Thursday, an episode that has strained medical resources and compounded challenges for U.S. personnel as military forces withdraw.

State Department spokesman Ned Price said a local staff member had died and scores more had been infected in a “significant” outbreak at the U.S. Embassy in Kabul.

Price, speaking to reporters in a phone briefing, said the embassy had “adjusted operations to ensure the continued safety, security and health of our staff,” a move that has included requiring employees to confine themselves almost entirely to their quarters within the bunkerlike facility.

“We do expect that normal embassy operations will resume once embassy leadership is confident the chain of transmission has been broken,” he said.

The outbreak occurs as Afghanistan suffers a devastating spike in coronavirus cases, straining the country’s meager health infrastructure. Cases have risen 2,400 percent in the past month, and fewer than 1 percent of Afghans are fully vaccinated, Reuters reported.

According to the American Foreign Service Association, a diplomats union, 114 embassy employees have been infected by the virus. It said several personnel had been airlifted from Afghanistan and that some others were being treated in an “emergency covid-19 ward” at the embassy because military medical facilities were at capacity.

“At a time when the U.S. military withdrawal is accelerating, attacks on Afghan and Coalition forces are intensifying and the U.S. is seeking to establish a stable and positive presence in Afghanistan after the withdrawal, the damage to our national security and national interests is potentially grave,” the association said in a statement on its website.

Price said 95 percent of embassy employees who had tested positive for the coronavirus were unvaccinated or not yet fully vaccinated, despite the fact that diplomatic personnel have had access to vaccine doses “for the past couple months now” in Kabul and other places.

He said the U.S. government would continue to encourage its employees across the globe to get vaccinated but noted that they were not required to do so.

In its statement, the Foreign Service Association called for mandatory vaccinations for all employees of U.S. missions except those who have medical or religious reasons for forgoing them.

The situation at the U.S. compound grows more severe after several embassies in Kabul, including the American one, stopped consular services over the past few days, citing the coronavirus outbreak. The decision could stymie the issuance of visas to thousands of Afghan interpreters and other people who have worked for the U.S. government, despite threats by the Taliban.

The top U.S. military headquarters in Afghanistan abuts the embassy. A U.S. official, speaking on the condition of anonymity because of the sensitivity of the issue, said the outbreak is complicating the withdrawal of U.S. military forces that President Biden ordered to be finished by no later than September.

To combat the virus, U.S. officials said that diplomatic employees will be confined to their quarters except to obtain food or spend time outside on their own.