International health organizations have generally been opposed to such coercive measures in fighting the epidemic, arguing that they add a punitive element, increase hardships for communities hit by the virus and diminish needed trust and cooperation.

On Saturday, a representative of one agency voiced similar reservations about Sierra Leone’s new policy, expressing doubts that it would be effective. He suggested that the government’s initial plan — to educate communities that may be harboring patients about the risks of such behavior — had mutated into something harsher. He asked not to be quoted by name because of the delicacy of the matter.

The group Doctors Without Borders, which has been working in the region, warned that the lockdown could make matters worse. “It has been our experience that lockdowns and quarantines do not help control Ebola, as they end up driving people underground and jeopardizing the trust between people and health providers,” it said Saturday, according to news agency reports.

But a top United Nations official in Sierra Leone said he supported the idea. “For three days we’ll go house to house to reach every household,” said Roeland Monasch, the Unicef representative in the country. “The reality is that the fight against Ebola will not be won in the Ebola clinic. By the house-to-house campaign, you try to stop transmission at the family level.”

The World Health Organization said Friday that the Ebola death toll in West Africa had topped 2,000 — the total number of confirmed, probable and suspected deaths is now 2,097 — with no sign that the outbreak is abating. Sierra Leone has recorded 491 deaths.