HAVANA, May 15 (Xinhua) -- The number of infected patients with the A/H1N1 flu has risen to three, after Cuban Public Health Ministry (MINSAP) confirmed two new cases in a statement issued on Friday.

    The statement said the new patients are Mexican youngsters who study medicine in Cuba and who have returned from the break they had in Mexico at the end of April.

    "The evolution of these three cases has been favorable. All of them have received anti viral treatment, and there have not been adverse reactions," the MINSAP said.

    The MINSAP also said that a group of 15 Mexican students are under medical observance, 11 of them were sent back home and four of them are hospitalized but their evolution is "favorable."

    Cuba has said that it has the sufficient anti-viral medicines to face the diseases, and that it keeps the sanitary measures and epidemic vigilance to reduce the risk.

    The World Health Organization (WHO) said in a report that it has confirmed the H1N1 flu cases in 34 countries.

    In Mexico the death toll for the H1N1 flu reached 66, according to information given on Friday by Mexican Health Ministry.