U.S. Customs and Border Protection’s Office of Professional Responsibility is investigating after images of Border Patrol agents confronting Haitian migrants on horseback in Del Rio circulated nationwide in September, the Department of Homeland Security said Tuesday.

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The incident was initially referred to DHS's Office of Inspector General, but the OIG declined to investigate and referred the matter back to CBP's OPR, a news release stated. 

OPR then immediately started investigating the matter, including reviewing videos and photos, as well as interviewing witnesses, employees and CBP leadership. 

Once completed, the results of the investigation will be provided to CBP management to determine whether disciplinary action is appropriate, according to the news release.

“The activity under investigation, which was captured in photographs and video that circulated nationwide, occurred during the large gathering of Haitian and other migrants near the International Bridge,” the release stated.

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At least two agents were placed on administrative duties following the incident, ABC News reported. 

CBP confirmed to ABC News the agents involved remain on administrative detail and the horse patrol unit is still suspended from operating in the city of Del Rio, which includes a narrow strip of the international bridge where a Haitian group gathered in September.