Japan confirmed its first cases of swine flu Friday as Mexico raised its death toll from the outbreak to 45.

Japan's Kyodo news agency said three males — a high school teacher and two teenage students — have the H1N1 influenza virus, said Reuters. They had recently returned to Japan via Detroit after spending time in Canada, said the report.

The three are in hospital, while 47 others who were on the same flight have been taken to a facility near Tokyo's Narita airport.

Earlier Friday, officials in Mexico confirmed one more death from swine flu. Mexican Health Secretary Jose Angel Cordova said tests also confirmed 159 more cases of swine flu, bringing the total number of people in Mexico sickened by the virus to 1,319.

Across the globe, there are 2,500 confirmed cases of the H1N1 influenza virus in 25 countries, the World Health Organization said during a Friday briefing.

The United States has 1,639 confirmed cases, including two deaths. One of the deaths was a woman with chronic health issues, while another was a Mexican infant visiting family in the U.S. A total of 44 people have died of the flu strain in Mexico.

The number of confirmed cases and deaths reported by the WHO may not match the numbers reported by countries because those countries may not yet have reported them to the international health body.

There are 243 confirmed cases of the outbreak strain of H1N1 in Canada.

Alberta confirmed nine new cases Friday, including the woman who died, for a total of 42. Ontario reported six new cases on Friday, bringing the total there to 62.

Quebec health officials said four new cases had been confirmed in that province on Friday, bringing the total there to 15.

Nova Scotia confirmed three more cases, bringing the total there to 56. British Columbia confirmed six new cases for a total of 60.

Prince Edward Island confirmed one new case for a total of three. Nearly all of the cases in Canada have been mild. Newfoundland and Labrador, as well as the three territories, haven't officially reported any cases.

The WHO also said Friday it plans to keep its global pandemic alert level at five out of six.

"We still remain in stage five. We have no evidence of community transmission," said Sylvie Briand, acting director of the WHO's global influenza program.

The current phase indicates there is sustained human-to-human transmission of the virus in at least two countries in one region.

Hong Kong hotel quarantine lifted

Also Friday, officials in Hong Kong released about 280 people from a weeklong quarantine at an upscale hotel.

The lockdown was imposed after a traveller from Mexico came down with swine flu. The patient has since been released from hospital.

Newly free guests of the Metropark Hotel walked to waiting buses, divided from waiting reporters by a security cordon — though some shouted out and others spoke by phone or email.

Critics said the quarantine was a politically calculated overreaction, but the Hong Kong government has repeatedly defended the measure as necessary to contain the virus. Hong Kong is also wary of repeating the fallout of severe acute respiratory syndrome, or SARS, which killed 299 people there in 2003.

Guests said they were well-treated during the quarantine, with one Australian man adding that "drinks have been flowing freely."

Hong Kong leader Donald Tsang greeted hotel staff after most guests dispersed.

"We all understand the boredom, the frustration they experienced during the quarantine period," Tsang told reporters. "We are thankful for the sacrifice they have made for the sake of public health."

With files from The Associated Press/The Canadian Press