Several thousand teachers blocked the main expressway leading to the airport; they had vowed to seize the terminal, but police were called in to block the march.
Travelers were forced to walk part of the way to the airport to catch their flights, according to the airport press office. Some fliers were ferried into the airport aboard police trucks once they reached police lines set up to prevent protesters from seizing the terminal.
Other travelers, both Mexican and foreign, were seen walking glumly up the expressway leading to the airport with suitcases only to find their path blocked by a line of riot police carrying shields on horseback.
Weary of almost a week of constant protests, Mexico City residents expressed anger at city authorities who seemingly allowed the teachers to block as many streets as they wanted.
Hundreds of striking teachers battled police at the Congress building and later blockaded streets around the building, forcing lawmakers to meet in a convention center to vote on the education reform bill, parts of which were approved by the lower house.
The protesters took over much of Mexico City's downtown historic district, erecting a vast tent encampment in the main plaza and surrounding streets.
The protesters have refused to move to make room for Sunday's Mexico City Marathon race, forcing organizers to reroute the run.
The marathon had been scheduled to conclude in the vast main plaza, but will now pass through a much smaller, more modest finish line.
The bill introduces teacher evaluations and reduces the power of corruption-ridden unions in hiring teachers, many of whom inherit their jobs from relatives under current rules.
Protesters say the reform relies too heavily on tests, and say student and parent evaluations and other factors should be taken into account.
Thousands of teachers belonging to the radical teachers' union, known as the CNTE, began gathering in Mexico City in recent weeks. The union's members have battled police in the past in the southern states of Oaxaca, Guerrero and Michoacan. In 2006, a union-led coalition seized almost the entire city of Oaxaca for nearly five months, until federal forces retook the city amid pitched battles.
But seldom has the largely rural union flexed its muscles in the nation's capital, where daily traffic is chaotic at best, and nightmarish at worst.
Patience was running out by Friday.
Guillermo Gazal, president of the downtown business group Procentrhico, said "the Mexico City government has acted irresponsibly by allowing CNTE protesters to seize the congress buildings ... reducing the city to a state of defenselessness and chaos that harms its residents, social, work and commercial activities."
Federal authorities and the airport's private management said they were drawing the line at the airport.
"This can't be like the other buildings they have tried to seize," said airport Director Alfonso Sarabia. "The operations at the airport cannot be interrupted, come what may. Over my dead body."
Mexico City police chief Jesus Rodriguez Almeida defended the non-confrontational approach of the city's leftist government. Past demonstrations have shown that the city's police do not have the training or skills to contain such protests without using excessive force.
"We are avoiding confrontation at all cost, to avoid bloodshed, to avoid this becoming a battle ground," Rodriguez Almeida told local media.
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