Authorities in Liberia say there have been dozens of new Ebola cases erupting along the border with Sierra Leone.
The announcement by Assistant Health Minister Tolbert Nyenswah on Monday marks a setback for Liberia, which has seen the number of cases stabilise somewhat after having been the hardest hit country in West Africa.
Nyenswah blamed the flare-up on a number of factors including people going in and out of the country and traditional practices such as the washing of bodies.
Nearly 3 400 people have died from Ebola in Liberia over the past year with nearly 8 000 cases, though health officials say the situation has improved especially in the capital, Monrovia.
Sierra Leone, by comparison, has now eclipsed Liberia with more than 9 000 cases, according to the World Health Organisation.