The U.S. military airlifted some embassy staff from Haiti amid spreading gang violence and sent security forces to better protect the U.S. compound there, officials said on Sunday.

Haitian officials declared a state of emergency last week amid a surge in violence in the capital of Port-au-Prince, including at the airport and at state offices.

The attacks began while the country’s prime minister, Ariel Henry, was out of the country.

Last week, armed groups took over the city’s main port and cut off access to food and supplies, worsening an already dire humanitarian situation. Attacks on prisons helped set thousands of inmates free. And more than 15,000 Haitians have been forced to flee their homes amid gunfire and murder.

A top gang leader has threatened “civil war” if Henry does not step aside.

The situation has quickly spiraled into one of Haiti’s worst periods of unrest and has complicated the U.S.’ position in a region where it has long held political sway.

The Biden administration has stressed it does not plan to send troops to the nation, but the White House encouraged Henry to assist in some sort of transfer of power.

The U.S. embassy said Sunday it realized there were few ways for Americans to leave the country, but said its ability to assist citizens was extremely limited.

“The current security situation in Haiti is unpredictable and dangerous. We are aware that there are few or no commercial options to depart Haiti safely at this time,” the embassy said in a statement. “As they become available, we urge U.S. citizens to take advantage of them.”

Officials urged those still in the country to update their crisis intake documents in case they need to be contacted by embassy staff.