The U.S. will shut down some of its embassies and consulates on Aug. 4 as a precautionary measure over security considerations, according to the State Department, which did not disclose further details, including the reason behind the closure, or the list of nations where U.S. diplomatic missions would be affected.

“The Department of State has instructed certain U.S. embassies and consulates to remain closed or to suspend operations on Sunday, August 4th,” Marie Harf, a spokesperson at the State Department said in a press briefing on Thursday, adding that “an abundance of caution and care for our employees and others who may be visiting our installations... indicates we should institute these precautionary steps.”

Harf said the diplomatic missions could remain closed for some additional days, adding: “Depending on our analysis, individual U.S. embassies and consulates will announce whether or not they are open and whether they are implementing restrictions or other measures.”

U.S. officials who spoke to Associated Press on the condition of anonymity said that the closures will be applicable to U.S. embassies and consulates in the “Muslim world,” where Sunday is a working day, and noted that U.S. diplomatic missions in Europe, Latin America and several other places do not operate on Sundays.

On Sept.11, 2012, the U.S. consulate in Benghazi in Libya came under attack from armed individuals, resulting in the killings of Chris Stevens, the U.S. Ambassador to Libya, his State Department colleague Sean Smith, and former Navy Seals Tyrone Woods and Glen Doherty.

The attack, which was initially tied to massive demonstrations in Libya at the time of the incident, was later termed a terrorist attack by top U.S. officials. At the time, the State Department had issued a security warning to U.S. diplomatic facilities throughout Muslim-majority nations, ahead of the anniversary of the 9/11 terrorist attacks in the U.S.

U.S. military bases and diplomatic missions in several Muslim nations were targeted by massive demonstrations in September last year, some of which turned violent. The protests were over “Innocence of Muslims”, a low-budget movie with anti-Islamic sentiments produced by a U.S. resident, portraying the Prophet Muhammad as a fraudster, womanizer and a child molester.

In February 2013, the U.S. embassy in the Turkish capital, Ankara, was targeted in a suicide bombing attempt by a member of an anti-U.S. and anti-NATO far-left group.