The United States has temporarily shuttered its embassy in Djibouti to the public to review security due to "ongoing threats," US officials said Wednesday.

The embassy in the Horn of Africa nation will be closed from Thursday, and will reopen for regular business on Sunday.

"We regularly get information and we decided to close to review our security posture in light of ongoing threats," a senior State Department official told reporters in Washington.

The closure comes as the U.S. mission in Riyadh remained closed to the public on Wednesday for the fourth straight day due to "heightened security concerns."

However, the State Department stressed that the two closures were "unrelated."

Djibouti is home to the biggest U.S. base in Africa, which is used for anti-terror operations in Yemen and Somalia as well as for other operations across Africa. France also maintains a military base in Djibouti.

On its website, the Djibouti embassy urged all U.S. citizens "to maintain a high level of vigilance and take appropriate steps to enhance your personal security" as well as to "follow instructions of local authorities" and read the State Department travel warnings.

Djibouti has a key port serving landlocked Ethiopia on the Gulf of Aden, commanding the entrance to the Red Sea. It is also used as a base for international anti-piracy operations.

The country is a key contributor of troops to the African Union force in neighboring Somalia, battling al-Qaida-linked Shebab militants.