The Mexican government has started to airlift food supplies to parts of the southern state of Oaxaca that it says are suffering shortages because of road blockades by striking teachers.
The first plane carrying 18 tons of corn arrived to the coastal city of Puerto Escondido on Thursday morning.
The authorities say the plan is to continue the airlifts until the weekend, moving a total of 100 tons of basic supplies to the area from where they can be distributed to state-subsidized stores in 300 impoverished communities.
"There are thousands of children without classes and without food," Interior Minister Miguel Ángel Osorio Chong told reporters. "We have to act because things cannot continue like this."
The teachers, meanwhile, have accused the government of inventing a food crisis in order to pave the way for a crackdown on their protests demanding the repeal of sweeping reforms that blame them for the dismal state of education in Mexico.
"This is a media campaign in order to justify actions aimed at clearing the blockades," said David Estrada, a teachers' leader from Oaxaca. "The government wants to make people have a bad opinion of the teachers."
Estrada, who belongs to the radical teachers union Coordinadora Nacional de Trabajadores de la Educación, or CNTE, said that some of the blockades are lifted at night and that food and fuel have always got through, though it might take "a bit more effort."
In the meantime the CNTE's national leadership has said it will intensify its protests over the next three days, reinforcing the barricades in Oaxaca and setting up new ones across the country. Just how dramatic the actions would be remained unclear on Wednesday, with members from the state of Chiapas announcing they would be allowing fuel trucks through their barricades.
The escalating tension comes as talks struggle to find a solution to a long-running conflict over the education reforms on which President Enrique Peña Nieto has staked his political legacy and which the striking teachers claim are a first step towards privatization.
The CNTE have always used periodic road blockades to put pressure on the government but has intensified the strategy in response to the government getting tougher on the implementation of the reform, and also the arrest of two key union leaders from Oaxaca.
The current round of negotiations began as an effort to calm things down after nine people died in clashes with federal police on June 19 at a road blockade outside the town of Nochixtlán, about an hour's drive outside of Oaxaca city.
Follow Alan Hernández on Twitter: @alanpasten