The American Embassy in Damascus reopened on Sunday for business after closing Thursday due to security concerns following a deadly US raid on Syrian territory near Iraq, a spokesman for the embassy confirmed. On Thursday, tens of thousands of Syrians in Damascus protested about a mile from the US embassy against last week's raid. "We reopened for business today," a spokesman told The Jerusalem Post on Sunday. "We were closed on Thursday for increased security concerns. Friday and Saturday were the normal weekend in Syria." While Washington has not formally acknowledged the raid, US officials have said it killed a top al-Qaida associate who organized the entry of fighters and weapons into Iraq. Syrian officials say the raid killed eight civilians and one high-ranking official has openly challenged Washington to prove the raid targeted an extremist. Last week, the Syrians asked State Department officials to close the American Cultural Center and the Damascus Community School - known as the American school-by November 6. On Friday, State Department spokesman Sean McCormack told reporters in Washington that they were still "considering how we're going to respond to that oral communication from the Syrians." In recent days, some experts have wondered whether the US raid on Syrian territory took place with Syrian knowledge or approval. "They crossed the border without encountering any aircraft fire from Syria. There is a theoryâ€¦ that maybe it was coordinated with the CIA and the Syrian intelligence," Moshe Maoz, a professor emeritus of Islamic and Middle Eastern Studies at the Hebrew University of Jerusalem, said last week. "Both have been working against al-Qaida." In the past, Syria has arrested some al-Qaida operators and given them to the United States, while the United States occasionally sends those working for al-Qaida to be tortured in Syria, Maoz said. Also on Saturday, Iraq sent police reinforcements to the Syrian border after the raid raised tension between Syria and Iraq. AP contributed to this report.