Mexico's Federal Electoral Institute says Felipe Calderon of the ruling National Action Party narrowly won the presidential election held a week ago.  It says Mr. Calderon won with 35.88 percent of the vote. His closest rival, Andres Manuel Lopez Obrador, received 35.31 percent. It was the closest presidential contest in Mexican history. The losing candidate, however, refused to accept the final result and wants a recount of every vote cast in the election.

These people say the election is not over. They chant that, if their candidate, Andres Manuel Lopez, is not declared the winner there will be a revolution.

Protest leader Gustavo Ortega Bravo says he and millions of others who supported Lopez Obrador have no confidence in the electoral system. He says they must mobilize nationwide to keep political leaders from ignoring their complaints.

But the demonstrations raise fears of violence and chaos for many Mexicans.

One woman worries that Lopez Obrador will provoke followers to aggressive actions.

Close to 60 percent of Mexico's registered voters showed up at the polls on Sunday, July second, in a process international observers called exemplary.

Since then, most Mexicans have followed developments in the news media, but have gone about their normal daily lives.

But leftist groups have shown they can shut down streets here in an instant, disrupting traffic and the daily routine of millions of city residents.

Election officials say there is no reason for strife as the law provides mechanisms to contest election results based on alleged irregularities.

But those who distrust the system and truly believe their candidate lost through fraud say they will continue to take their complaints to the streets.