Amateur video reportedly from a Syrian activist shows what weapons experts from Human Rights Watch and the Geneva International Center for Humanitarian Demining believe are the remains of cluster bombs near the restive area of Hama.
"If confirmed, this would be the first documented use of these highly dangerous weapons by the Syrian armed forces during the conflict," said Steve Goose, arms division director at Human Rights Watch, in a statement from New York.
Syrian forces in June were accused of killing at least 78 people in the Qubeir settlement in the Syrian province of Hama. U.N. Secretary-General Ban Ki-moon described the reports coming out of the region as "sickening."
The rights organization said Syria has no history of using or producing cluster munitions, though it includes the controversial weapons in its stockpile.
The conflict in Syria has entered its 16th month. Defected Syrian Ambassador to Iraq Nawaf Fares was quoted by The Wall Street Journal as saying from Qatar he has joined "the ranks of the people's revolution in Syria."
More than 30 Syrian military officers crossed over into Turkish territory to defect last month.