The top U.S. commander overseeing operations in Africa said Tuesday that a small number of U.S. troops would be involved in treating patients with the Ebola virus directly, contradicting previous U.S. officials who said they would have no direct involvement with them. But the general corrected the record a short time afterward, saying they will work only with samples from patients.

The confusion came out of a news conference at the Pentagon, and underscored the sensitivities surrounding the deployment to West Africa of up to 4,000 U.S. service members as part of Washington’s response to the public health crisis. The Obama administration has said repeatedly that no U.S. troops would be involved in treating patients, and would instead focus primarily on constructing treatment centers and providing logistical support to health workers, including transportation.

But Gen. David Rodriguez, chief of U.S. Africa Command, said Tuesday that a small number of highly trained medical professionals in the military would treat Ebola patients in mobile laboratories.

“The mobile [labs] are testing people, OK? And some of them will have the Ebola virus,” Rodriguez said. “Now, those are trained at the highest level of something like nuclear, biological and chemical. So they’re all trained at a very, very high level.”

Rodriguez said that the laboratories would each have a three- or four-person team, and that there were three labs already deployed. Several more labs likely will be added, he said.

The general released a follow-up statement through the Pentagon Tuesday afternoon. In its entirety, it said:

“In response to comments I made today about U.S. military personnel potentially coming in direct contact with Ebola infected individuals, specific to lab testing, I want to clarify my remarks. U.S. military personnel working in the labs are not interacting with patients, only samples. The testing labs are manned by highly skilled and trained personnel from the U.S. Naval Medical Research Center. These labs provide 24-hour turnaround results on samples received from area clinics and healthcare providers, with the capability to process up to 100 samples per day.”

U.S. troops will be based in several countries in West Africa, including Liberia, at the heart of the ongoing Ebola crisis that has killed more than 3,400 people worldwide, according to the World Health Organization. They will be monitored several times per day for Ebola symptoms.