LOS ANGELES -- Two "probable" and two "possible" cases of swine flu were being investigated in Los Angeles County Tuesday, and while test results were pending on a man whose death was initially suspected of being linked to the disease, health officials said the man was likely a victim of seasonal flu or pneumonia.

Dr. Jonathan Fielding, director of the Los Angeles County Department of Public Health, told the Board of Supervisors that there were still no confirmed cases of swine flu in the county, but he said, "of course, they are expected."

"We currently are investigating two possible flu clusters in two schools located in the Santa Clarita Valley," he said. "We have at this point two probable cases and two possible cases of swine flu."

The county coroner's office reported earlier that it was investigating two deaths as possibly stemming from swine flu, but Fielding downplayed those reports. One case -- the death of a 45-year-old La Mirada man -- was ruled out as a swine flu case.

"There were two cases that were apparently misreported. One is definitely not swine flu and the other one is still being looked at," Fielding said.

The case still being examined is a 33-year-old Long Beach resident who exhibited flu-like symptoms before he died Monday afternoon at Bellflower Medical Center, coroner's spokesman Ed Winter said. Although it will likely be another 24 to 48 hours before test results are finalized, Winter said swine flu is not expected to be the cause of death.

"It could be, however, the symptoms that he went into the hospital with were not anything like the swine flu," Winter said.

Although no cases have been confirmed, the Board of Supervisors declared a local health emergency until further notice.

The declaration is designed to facilitate Fielding's ability to address the issue by authorizing him to manage local, state and federal supplies and services with costs up to $500,000 for swine influenza-related activities.

Fielding and other county health officials said the disease is likely already present in the county, and just has not been reported. The disease resembles regular influenza, so people may not distinguish it from a common flu, said Dr. Laurene Mascola, director of the county's Department of Public Health's Acute Communicable Disease Control.

Fielding said there are generally 1,000 deaths in the county from season flu every year.

Meanwhile, tests were pending to determine if the mother of a student at Our Lady of the Assumption School in Claremont had swine flu or another illness. The woman developed flu symptoms, and her daughter became slightly ill, four days after they returned from a trip to Mexico.

Both have been tested for swine flu, according to the Roman Catholic Archdiocese of Los Angeles, which runs the school, which was closed Tuesday but was expected to reopen Wednesday after undergoing a thorough cleaning.

A total of 11 cases have been documented in California -- five in San Diego County, five in adjacent Imperial County and one in Sacramento. At least another six people in San Diego County are suspected of having contracted the disease, and there were unconfirmed reports of two additional cases in Sacramento and two in Marin County.

A total of 64 cases of swine flu have been confirmed in six states, according to the Centers for Disease Control and Prevention. No fatalities have been reported.

The disease is most prevalent in Mexico, where about 2,000 people have developed influenza and about 150 are suspected of dying from the disease. Only 26 of them had been confirmed as of this morning to have been swine flu sufferers. Cases of swine flu also have been confirmed in Canada, Scotland and Spain. Unconfirmed cases have been reported in New Zealand, France and Israel.

Starting Tuesday, public health officials had the proper facilities to test for swine flu. Previously, only the Centers for Disease Control in Atlanta had the ability to check for the strain.

Dr. Mark Horton, director of the California Department of Public Health, said about one-fourth of the federal stockpile of 5 million courses of vaccines targeting the disease have been sent to Sacramento for possible distribution to local jurisdictions, if needed.

About 625,000 courses of antiviral medication were expected to be made available to Los Angeles County, adding to the county stockpile of 49,000, said Dr. Alonzo Plough, director of the Los Angeles County Public Health Emergency Response.

An additional 1.8 million courses in state and federal reserves could potentially also be made available to the county, he said.

Physicians say that the antiviral treatments should not be taken as a preventative measure, but rather in consultation with a doctor if a patient is suffering from flu-like symptoms. Taking such drugs as Tamiflu and Relenza prophylactically, if they turn out not to be needed, could only make the virus drug-resistant, they say.

Several measures were being taken to guard against the spread of the potentially deadly disease. Workers at Los Angeles International Airport, where 45 flights from Mexico arrive daily, were disinfecting restrooms to try to stop the spread of the disease.

Swine flu is usually transmitted to humans by pigs, but public health officials said they were concerned about the possibility of a pandemic because the new strain appears to be spreading from human to human.

U.S. Homeland Security Secretary Janet Napolitano announced a nationwide health emergency Sunday.

California Superintendent of Public Instruction Jack O'Connell said parents should not be worried about sending their children to school.

"Our schools in California are safe," O'Connell said, noting that to date only a few children out of a state enrollment of 6.3 million students have been infected.

In Mexico City, people have taken to wearing surgical masks, and the government has closed schools and canceled public events, including church services, in an effort to control the spread of the disease.

Mascola said that the surgical masks could actually make problems worse by providing a false sense of security, and that they were not recommended as a preventative measure.