Israel is to vaccinate 15,000 security and rescue workers against smallpox in case of possible biological attack by Iraq if the US launches military action.

This is part of preparations for a "very unlikely scenario", a spokesman for the Israeli prime minister said.

It's a very remote contingency

Israeli spokesman Raanan Gissin

The spokesman, Raanan Gissin, said rescue workers and security officials would be inoculated in case they had to be called into action.

Firefighters and ultra-Orthodox rescue workers will also be vaccinated.

No start date has been announced.

Israel fears Iraq could react to a US strike by attacking Israel as in the 1991 Gulf War.

Israel has also been stepping up its missile defences

During that conflict, Iraq fired more than 30 Scud missiles at Israel.

At the time, Israelis were given gas masks as a precaution against chemical attack, but all the missiles were carrying conventional warheads.

The Health Ministry has said it would begin vaccinating the whole population if the US attacks Iraq.

It recently announced it had enough smallpox vaccine for the entire population of more than 6 million, as well as tourists and hundreds of thousands of foreign workers.

It did not say if it would inoculate more than 3 million Palestinians in the West Bank and Gaza Strip, according to the Associated Press.

The US has said it wants to see the Iraqi leader Saddam Hussein removed from power, but has not yet publicly confirmed that it will go war to achieve this.