Mexican Health Minister Jose Angel Cordova Villalobos late on Sunday raised the death toll of the A/H1N1 flu to 22 and the number of infected cases to 568 in the country.

The figures were up from the earlier announcement by the government which said death cases remained unchanged at 19 for several days and the number of infected cases was 506.

The official data showed that the disease has spread to 23 of the nation's total 32 states with the capital and its surrounding area seeing the majority of the infected cases.

Some 53.8 percent of the samples that tested positive were from women, and 46.2 percent from men.

Children aged below 10 accounted for some 24.1 percent of the total infected, becoming the largest age group. Children aged 10 to 19 and adults aged between 20 and 29, tied in the second place with each occupying 23.7 percent, while the fourth largest group with 13.6 percent was those aged 30 to 39.

"We must not weaken our guard," the minister told a press conference earlier Sunday, indicating that the government will take further measures if more cases are found.

Last week, the Mexican government closed all educational institutions from nurseries to universities, sending home around one third of the population. It also called for no mass gatherings and asked all residents to stay at home as much as possible.

The government is also urging Mexicans to wash their hands frequently, to wear face masks in public area, to avoid shaking hands and to go to the doctor at the first onset of flu-like symptoms.