Three more states in the U.S. on Monday reported their first death of A/H1N1 flu.

In Boston, director of the city public health commission Barbara Ferrer said at a news conference that a woman in her 30s is the first A/H1N1 flu-related death in the state of Massachusetts, where confirmed cases of A/H1N1 flu reached 1,153 last Thursday.

State and city health officials said the woman died on Sunday had some other health problems but they are not sure if they directly contributed to her death.

"We believe very much that this is a reminder that flu can be serious," said John Auerbach, the state commissioner of department of public health, quoted by local reports.

In the state of New Jersey, the A/H1N1 flu virus is being blamed for the death of a 49-year-old man, the first fatality in the state associated with the virus, health officials said on Monday.

The man died in hospital Saturday, according the health officials who believed that the man had multiple underlying conditions, although they did not specify what they were.

As of Monday, the state had reported 320 confirmed cases of the A/H1N1 flu as well as 194 probable cases in 19 of the state's 21 counties.

Meanwhile, Minnesota health officials announced a child from the Twin Cities was the first person to die of A/H1N1 flu in the state.

The child had died late last week after a brief hospitalization, according to state medical epidemiologist Aaron DeVries who said the child had multiple medical conditions before falling ill and Lab tests confirmed the A/H1N1 virus.

"Clearly the underlying health problems played a major role in why this child became so sick," said DeVries.

The state health officials have so far confirmed 274 cases of A/H1N1 flu in Minnesota.

But they admit they have been only testing people at high risk for complications, such as those whose immune systems are compromised, pregnant women, health care workers and hospitalized patients.

"The best analogy is an iceberg where we're only detecting the top portion," he said.

Nationwide, the federal Centers for Disease Control and Prevention on Friday reported 45 deaths of A/H1N1 flu, but local health officials believe the real number could be much higher.