A White House official says the United States thinks it is "extremely unlikely" Turkey used chemical weapons against the Kurds.
The official says that they are aware of the reports, but cannot confirm them and called for the protection of civilians.
Local doctors and Syria's state-run news agency reported Saturday that six civilians suffered breathing difficulties and other symptoms indicative of poison gas inhalation after an attack launched by Turkey on the Kurdish-controlled enclave of Afrin.
State-run news agency SANA and the Britain-based Syrian Observatory for Human Rights monitoring group also quoted local doctors in their reports.
The claims could not be independently verified, and videos released from the hospital showed people being fitted with oxygen masks who did not otherwise show symptoms of poison gas inhalation.