FREETOWN, Sierra Leone (AP) — Thousands of health workers began knocking on doors across Sierra Leone on Friday in search of hidden Ebola cases with the entire West African nation locked down in their homes for three days in an unprecedented effort to combat the deadly disease.

Authorities hope to find and isolate Ebola patients who have resisted going to health centers, which are often seen only as places to die. International health experts, including Doctors Without Borders, have warned such a strategy could backfire especially if there are not enough beds at treatment centers for all the new patients found.

In an address to the nation late Thursday, President Ernest Bai Koroma said health workers would be handing out soap and that once a house had been visited it would be marked with a sticker. He urged Sierra Leoneans to abide by the order.

"The survival and dignity of each and every Sierra Leonean is at stake; all what we have toiled for as a people is at stake; this is a fight for each and every one of us; this is a fight for this land that we love," he said.

More than 2,600 people have died across West Africa, with more than half the fatalities recorded in Liberia.

Earlier this week, President Barack Obama pledged 3,000 troops and the first increased American military aid arrived in Liberia on Thursday, according to the U.S. Embassy there.

The C-17 U.S. military aircraft brought a team of seven military personnel along with some equipment on Thursday. An embassy statement said more supplies and personnel are expected in the coming days.

Meanwhile, six people have been arrested in connection with the killings of eight people in Guinea who had been on an Ebola awareness campaign in a rural area, the Guinean government said Friday. The team, accompanied by journalists, had gone to the village of Womey on Tuesday. Another team dispatched to Womey to look for nine missing members discovered eight bodies, including those of three local journalists, a hospital administrator and several health officials, the government said in a statement.

Only one of the missing, the son of a Womey deputy administrative leader, was found alive, and hiding in the area, the statement said.

Many villagers in West Africa have reacted with fear and panic when outsiders have come to conduct awareness campaigns and have even attacked health clinics, believing they are spreading the disease.

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Associated Press writer Jonathan Paye-Layleh in Monrovia, Liberia, and Boubacar Diallo in Conakry, Guinea, contributed to this report.