Israel detected its first cases of H5N1 bird flu on Friday, saying the virus had killed thousands of turkeys and chickens on two farms.
The Israeli authorities also treated three people in hospital on suspicion of having the virus.
Bird flu has spread with alarming speed in recent weeks across Europe, Africa and parts of Asia, stoking fears the virus could mutate into a form that could easily pass from one person to another, triggering a pandemic in which millions could die.
Three people who worked in poultry coops at the farms where the virus was discovered were admitted to isolation units at Soroka Medical Center in the southern Israeli city of Beersheba.
“All those who were in contact with fowl and have some sort of illness ...will be put in quarantine. Until proved otherwise ...they have bird flu,” said hospital director Eitan Hayam. However, he said there was only a slim chance they had contracted the virus.
Two farms were confirmed to have infected poultry. Tests were being carried out another two farms where H5N1 is suspected.
Police put up roadblocks around the farms to prevent movement of people and fowl, and agriculture officials said hundreds of thousands of birds might need to be destroyed to contain the outbreak.
In a rare act of cooperation, Israel was also testing dead fowl found in the West Bank and Gaza on behalf of the Palestinian Authority to try to control the spread of the virus.
However, it is unclear what the scale of cooperation will be once a Hamas-led government takes office in Palestinian areas. The Islamist group, expected to name its cabinet within days, won elections in January and Israel has vowed not to have direct contacts with it.
An Israeli agricultural ministry official said vets on either side could still work together.
Fears for humans
Although it is hard to catch, people can contract bird flu after coming into contact with infected birds. The World Health Organisation says at least 98 people have died from H5N1 so far.
Three women who died in Azerbaijan recently are also thought to be bird flu victims, but the WHO is awaiting the results of further tests before confirming the cause of deaths.
Tests were also being carried out on a sick Serbian boy from a village near the border with Bosnia where bird flu had been identified in birds.
The risk of human infection means people must wear protective clothing when culling birds in areas where H5N1 has broken out. In Afghanistan, where bird flu was confirmed on Thursday, a lack of protective suits is delaying efforts to stop its spread, an agriculture ministry official said.
In further evidence of bird flu continuing to spread, Sweden confirmed it had found the H5 virus in a duck on a game farm in the east of the country, the European Union executive said.
Bird flu has shaken poultry markets around the world as consumers have lost their appetites for chicken, with some countries reporting a drop in sales of up to 70 percent.
The EU banned poultry imports from Israel after the discovery of H5N1 there, the EU’s executive Commission said.
The French poultry industry, which has been hit by a series of bans on its products after the discovery of an H5N1 outbreak on a turkey farm, received a little comfort on Friday with news that fewer birds than expected may be culled in the area of eastern France where the virus was detected.
But in Greece, the mood was less positive.
“Give it another two or three months and we can then talk about a complete disaster, the end of our sector,” poultry business federation chief Spyros Nonikas told Reuters.