MOSCOW (AP) - Russian health authorities said Monday that their nation is ready to offer assistance if the United States needs help in combatting anthrax.

"We are ready to supply the United States with vaccines against anthrax if the necessity arises," said Lyubov Voropayeva, a spokeswoman for the Health Ministry's chief public health officer, Gennady Onischenko.

Jitters about bioterrorism have spread since anthrax cases were confirmed last week in Florida and New York and the bacteria was found on a letter in Nevada. As of Monday, a dozen people around the United States either have anthrax or have been exposed to it.

The FBI is investigating those cases, and addressing whether there is a possible link to the Sept. 11 terrorist attacks against the United States that killed thousands of people.

"If these cases really have a terrorist origin, one should be prepared to protect the public," Health Minister Yuri Shevchenko told reporters.

Anthrax produces a toxin that can cause fatal damage to the respiratory system and brain. It can be treated with antibiotics, but treatment must begin rapidly.

The anthrax scare began Oct. 4 when it was confirmed that a Florida man had contracted the inhaled form of the bacteria. He later died, the first such death in the United States since 1976.