MEXICO CITY, Mexico – Sunday morning outside the Metropolitan Cathedral a sign reads "NO MISAS" - no mass.

The plaza outside the cathedral is virtually empty, the normal large Sunday crowd of tourists and worshippers seem to be following the advice of government officials, to avoid large crowds.

Police outside a Mexico City cathedral trying to keep worshippers away on Sunday.

We met Carla Casas, a woman who appeared to be in her mid-20s. Carla was scheduled to be confirmed at the 8am mass. She showed up wearing a mask and told us she's very afraid that she and her family could get sick.

"I heard that people are dying 48 hours after getting sick. I'm very concerned" she told us.

Carla also said she thought the "swine flu" originated from the United States. We've heard the same story from several other people who say they heard that from the Mexican media.

Not everyone we've talked to is scared of getting sick.

One young man, a university student, said he thinks the government is going too far by closing schools and other events.

Across the city, police and members of the Mexican army are handing out masks to people on the streets. There is a clear sense of tension here as people wait to see what happens.