Members of an NBC News crew who traveled to Africa  and worked with a cameraman who contracted Ebola in Liberia have been ordered under a mandatory quarantined, New Jersey health officials said.

The order was issued late Friday after the crew members violated an agreement to voluntarily confine themselves.

Meanwhile Reuters reports that the condition of the freelance American cameraman continued to improve. At Nebraska Medical Center, Ashoka Mukpo, 33, has received the experimental drug Brincidofovir and a blood transfusion from Dr. Kent Brantly, who earlier recovered from a bout with Ebola at Emory University Hospital in Atlanta. Brantly also contracted the disease in Liberia.

Mukpo "is eating some solid food now, so we're still headed in the right direction," said Dr. Phil Smith, director of the biocontainment unit at Nebraska Medical Center.

The NBC News crew had agreed with health officials to stay in their homes after returning to the United States but then failed to do so, Donna Leusner, a spokeswoman for the New Jersey Department of Health, said in a statement.

The mandatory quarantine will ensure the group remains confined until Oct. 22, the end of a 21-day maximum incubation period for Ebola, Leusner said.

"The NBC crew remains symptom-free, so there is no reason for concern of exposure to the community," she said.

NBC News has reported that the crew that worked with Mukpo included its medical correspondent Dr. Nancy Snyderman.