A man who was diagnosed with the Ebola virus in the US state of Texas came in contact with young children, according to Texas Governor Rick Perry.
Experts are monitoring the children for any signs of disease.
"Today we learned that some school-aged children have been identified as having had contact with the patient and are now being monitored at home for any signs of the disease," Mr Perry said at a news conference.
"These children have been identified and they are being monitored and the disease cannot be transmitted before having any symptoms," he added.
US health officials are investigating how many people may have come in close contact with the patient, who travelled from Liberia to Texas to visit family.
He arrived on 20 September, but did not show symptoms until 24 September.
He sought medical care two days later, but was sent home before being isolated in hospital on 28 September.
His case is the first diagnosis of Ebola outside of West Africa in the largest outbreak of the disease in history.
Meanwhile, the World Health Organisation has released a statement indicating that even under best conditions, a significant number of Ebola vaccine doses will not be available until “late in the first quarter of 2015”.
The epidemic has killed more than 3,000 people since the beginning of the year.
