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

Wooden tables lay empty at the capital's usually vibrant food markets. Police stood guard at roadblocks in this nation of 6 million people. This crumbling seaside capital, its streets normally crowded with bumper-to-bumper traffic, seemed like a ghost town.

Health workers planned to give each household a bar of soap during neighborhood canvassing. Once a house is visited it is to be marked with a sticker. President Ernest Bai Koroma urged Sierra Leoneans to cooperate.

"The survival and dignity of each and every Sierra Leonean is at stake," he said Thursday night in an address to the nation.

At least 562 people are believed to have died from Ebola since the virus came to Sierra Leone from neighboring Guinea.

Authorities hope to find and isolate Ebola patients who have resisted going to health centers, often seen only as places to die. Some international health experts have warned there might not be enough beds at treatment centers for new patients found during the three-day lockdown which ends Sunday.

UNICEF said the measure provides an opportunity to tell people how to protect themselves.

"If people don't have access to the right information, we need to bring life-saving messages to them, where they live, at their doorsteps," said Roeland Monasch, UNICEF Representative in Sierra Leone. In a statement, the U.N. children's fund said the operation needs to be carried out "in a sensitive and respectful manner."

Most seemed to be taking the order seriously, and there were no immediate reports of resistance to the lockdown.

"It will protect our country from this dangerous virus," said Ishmail Bangura, a Freetown resident. "Many of our people have died — nurses and doctors too — so if they ask us to stay home for three days, for me it not bad."

However during this first-ever Ebola outbreak in West Africa, some people have previously lashed out at health workers, accusing them of bringing the dreaded disease. Others don't believe it exists. Many villagers in rural Guinea have reacted with fear and panic when outsiders conducted awareness campaigns, and this week such an encounter resulted in deaths.

Six people have been arrested in the killings of eight people in Guinea who were on an Ebola awareness campaign, the Guinean government said Friday. The team, accompanied by journalists, had gone to the village of Womey on Tuesday. Another team dispatched 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.

Only one of the missing — the son of a Womey deputy administrative official — was found alive and hiding in the area, the government statement 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. An embassy statement said more supplies and personnel are expected in the coming days.

___

Associated Press writers Kabba Kargbo in Freetown, Sierra Leone; Jonathan Paye-Layleh in Monrovia, Liberia, and Boubacar Diallo in Conakry, Guinea, contributed to this report.