Mexico is reporting the biggest increase in the number of people with A(H1N1) flu since the outbreak started this year.

The Mexican health ministry says 5400 more patients have been confirmed as having flu within a few days. Ninety percent of the cases are of A(H1N1), also known as swine flu and - in the Netherlands - as Mexican flu, and the remaining 10 percent are of ordinary seasonal flu.

The dramatic increase in the infection rate is being blamed on Mexico's present cold weather. Over 400 people have died as a result of A(H1N1) so far in Mexico. The flu pandemic has killed more than 6000 worldwide.

photo: face masks distributed in Mexico (ANP/EPA)