Switzerland has temporarily closed its embassy in Tehran because of an “increasing security risk”, authorities said late on Wednesday.

The Swiss government said its ambassador in Tehran and five staff members left Iran by land earlier in the day and are now safe outside the country.

They are expected to return once the security situation improves.

“They will return to Tehran as soon as the situation allows,” the government said in a statement.

About a week earlier, Swiss officials said the embassy had six Swiss employees and 18 locally hired staff.

Four Swiss nationals working at the mission had already left Iran on March 3.

For decades, Switzerland has also represented U.S. interests in Iran.

The U.S. embassy in Bern said Washington “respects the Swiss government’s decision” and expressed gratitude for the diplomatic mission’s work and its staff.

Their efforts “remain essential to protecting U.S. interests and supporting our citizens”, the statement added.

The Swiss government said that, in consultation with the countries concerned, it would continue to maintain communication channels between Washington and Tehran.

Switzerland has served as the U.S. protecting power in Iran since diplomatic relations between the two countries were severed.

In that role, it relays messages between the governments and provides assistance to U.S. citizens when needed.

(dpa/NAN)