Sierra Leone has recorded four new cases of Ebola in a village on its northern border and will likely see more infections in a further setback to efforts to end an 18-month West African epidemic, a senior health official said on Tuesday.

The new cases recorded since the start of the weekend in Sella Kaffta, a village in Kambia District, were all individuals who came into direct contact with a woman who died of the disease late last month.

Pallo Conteh, head of Sierra Leone's National Ebola Response Centre, said the woman's family had failed to notify authorities when she fell ill and instead cared for her themselves.

"I am expecting more cases," he said. "We are sure that the body was washed ... so all those who took part in the washing of the corpse, all those who were helping her when she was having wet symptoms would all become infected."

While soldiers and police have been brought in to ensure that over 1,000 villagers remain in their homes during a quarantine period, Conteh said one individual who had been in contact with the dead woman was still missing.

Authorities were attempting to track her through her telephone communications, he added.

The tradition of washing bodies before burial has been one of the primary sources of transmission over the course of the regional epidemic, which has killed over 11,300 people mostly in Sierra Leone, Liberia and Guinea.

Intensive information campaigns about the risks of such practices have been partly credited with slowing the progression of the epidemic and even ending the outbreak in Liberia, which was declared Ebola free last week.

But they have also met with resistance.

"Our people are stubborn," Conteh said. "Until they stop doing what I call the silly things we will have cases popping up here and there."

The death of the woman in Kambia last month came less than a week after the last person previously confirmed to have had the disease was released from hospital, raising hopes that the outbreak was coming to an end.