Mexico City, Mexico — Thousands of striking teachers strangled traffic and blocked access to Mexico City’s international airport last Friday, flexing their muscles in a bid to block educational reforms intended to introduce teacher evaluations and reduce union power over hiring decisions.

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.