Residents in Sierra Leone's remaining Ebola hotspots will be confined to their houses for three days next week, officials said, as the government tries to snuff out an outbreak that has killed over 10,200 people across West Africa.
The number of Ebola cases in the region has fallen in recent months, though a spike in Guinea highlights the risk of complacency, over a year into the worst outbreak on record.
Sidi Yaya Tunis, an official at Sierra Leone's National Ebola Response Centre, said health officials would carry out house-to-house searches from March 27-29 to identify the sick in the north and west, where the virus is spreading fastest.
Elsewhere, where transmission is lower, officials will focus on education and prevention, he said.
Health officials said a previous lockdown in Sierra Leone in September was a success and helped identify more than 100 cases.
"If we don't get on top of this before the rains come, it will be a horror show," said a Sierra Leone health official who asked not to be named because the details of the lockdown have not been made public. "Many people are still not following the basic rules."
The rains are due to begin in May. The World Health Organization has said they could greatly complicate the fight against Ebola by washing away roads and making it harder for aid and healthcare workers to get to affected areas.
The official said that residents would be allowed out to attend church on Palm Sunday for a few hours.
The latest figures issued by the WHO showed that there had been 10,216 confirmed, probable and suspected deaths from Ebola in West Africa.
Regional leaders have set themselves a target to completely stamp out the disease by mid-April. Ebola outbreaks in Nigeria, Mali and Senegal have been contained.
Liberia has recorded the most deaths with 4,283 since the crisis began, according to the WHO. However, there are currently no confirmed cases in the country.
Sierra Leone has been the next worst affected country with 3,702 dead.
Guinea, where the outbreak was first identified, has recorded 2,231 confirmed and probable deaths from Ebola but has seen a recent spike, with the number of patients more than doubling since last month.