MOGADISHU, Somalia — The United States has ordered all non-essential employees of its mission to Somalia to leave the capital, Mogadishu, because of “specific threat information” against them.

The order came a day after the U.S. military carried out its first drone strikes against Islamic State group-allied fighters in Somalia, saying “several terrorists” had been killed in the northern Puntland region.

Somalia remains one of the world’s most dangerous countries. The U.S. hasn’t had an embassy there since 1991 and calls security “extremely unstable.” The U.S. Mission to Somalia has been based in neighboring Kenya, and it is not clear how many employees may be based in Mogadishu.

Offices for a permanent diplomatic presence were expected to open in Mogadishu late this year, the first U.S. ambassador to Somalia in a quarter-century told Radio Muqdisho in June.

The U.S. mission did not respond to requests for comment

The new threat information relates to Mogadishu International Airport, the U.S. statement said Saturday. Several countries have embassies at the heavily fortified airport.

Mogadishu was rocked last month by the country’s worst attack, which killed more than 350 people and has been blamed on the Somalia-based al-Shabab extremist group. Somali intelligence officials have said the massive truck bomb was meant to target the airport but instead detonated in a crowded street after soldiers opened fire and flattened one of the truck’s tires.

Somalia’s small but growing number of ISIS-linked fighters are said to have switched allegiances from the al-Qaida-linked al-Shabab in the past few years.