MANILA: The Philippine health secretary urged Filipino boxing idol Manny Pacquiao to postpone his triumphant return home after beating Ricky Hatton to help prevent the spread of swine flu from the United States.

Health Secretary Francisco Duque III told reporters the World Health Organization made the "strong recommendation" for Pacquiao and his entourage to remain in Los Angeles and observe self-quarantine until next week because the virus was found to have spread to the city.

Duque said there are concerns that Pacquiao's motorcade - which will drive through Manila to mark a "national day of celebration" on Friday in honor of his victory - could pose a risk of spreading the virus if he or anyone in his group is infected. The Philippines has yet to confirm its first case of swine flu.

He said health authorities have been trying to contact Pacquiao to urge him to impose self-quarantine and delay his trip until at least Tuesday since it takes about five days for symptoms to appear.

"It is better to be conservative," Duque said.

Pacquiao's entourage drove from Las Vegas to Los Angeles to celebrate his second-round knockout victory Sunday over Hatton.