ISIS militants have captured a largely vacant neighborhood in Damascus in a surprise nighttime attack on pro-regime forces, the Syrian Observatory for Human Rights said on Monday. The Observatory said militants seized al-Qadam, which lies in the Syrian capitals southern suburbs, a week after Syrian rebels had surrendered the neighborhood to the regime. It said 36 pro-regime fighters were killed in clashes, and dozens more wounded or captured, adding the regime has sent reinforcements into the area. The district of al-Qadam has not been part of the month-long offensive waged by Syrian forces against rebels in eastern Ghouta. Earlier, ISIS claimed to have captured Qadam in a statement circulating on Twitter. ISIS has lost almost all its territory in Syria after two rival offensives last year by the Syrian forces, backed by Russia and Iran, and an alliance of Kurdish and Arab militias backed by the United States. It now controls only the small pocket in Qadam, and two small areas of desert on each side of the Euphrates near the border with Iraq.