All United States government facilities, including embassy premises and consulates throughout South Africa, remained closed for a second day Wednesday as a result of unspecified threats to their security.

The closure of the offices on Tuesday was announced at short notice by the U.S. Embassy in Pretoria. In a notice issued Monday, it asked U.S. citizens "to remain extra vigilant while in the vicinity of our facilities" and encouraged them to review a world-wide terrorism alert which the U.S. Department of State issued in July.

In a notice posted on its website, the embassy first said it assumed the offices would reopen on Wednesday. However, later it issued a notice saying they would remain closed "based on information recently received by the regional security office." Since Thursday is a national holiday in South Africa, the offices will remain closed on that day also.

The Johannesburg daily, Business Day, reported that South Africa's police minister, Nathi Mthethwa, said the police were working with American agencies to guarantee the security of U.S. offices in South Africa.