Sierra Leone has passed a new law imposing possible jail time for anyone caught hiding an Ebola patient - a common practice that the World Health Organization (WHO) believes has contributed to a major underestimation of the current outbreak.

The law passed on Friday imposed prison terms of up to two years for violators, lawmaker Organisation Jaiah Kaikai said.

He said the measure was necessary to compel residents to cooperate with government officials, noting that some residents had resisted steps to combat Ebola and build isolation centres in their communities.

A total of 2,615 infections and 1,427 deaths have been recorded in the Ebola outbreak now hitting West Africa, according to figures released on Friday by the WHO.

Sierra Leone has been hard-hit, with at least 910 cases and 392 deaths.

These numbers, however, do not capture all Ebola cases because families hide patients, fearing high fatality rates and the stigma that comes with a positive diagnosis, the UN health agency said.

New treatment centres in Liberia are being overwhelmed by patients that had not been previously identified, suggesting an "invisible caseload" of patients that is going undetected, the agency said.

Lawmakers in Sierra Leone's capital Freetown voted overwhelmingly in favour of the 2014 Public Health Amendment Act, which amends a 54-year-old public health ordinance.

Travel restrictions

Countries in the region and elsewhere in Africa have continued to impose travel restrictions, even though this hasn't been recommended by the UN.

Ivory Coast announced late on Friday it was closing its land borders with Guinea and Liberia.

Gabon, Senegal, South Africa and Cameroon have all imposed border restrictions on some or all of the four countries with confirmed Ebola cases - Guinea, Liberia, Sierra Leone and Nigeria.

Brussels Airlines, Belgium's largest carrier, said it was cancelling flights to the capitals of Guinea, Liberia and Sierra Leone for Sunday and Monday.

On Saturday, the Philippine government said it was recalling 115 peacekeepers from Liberia because of the health risks posed by Ebola.