Teachers reportedly blocked the entrance to Acapulco airport in protest over what they regard as an unfair investigation into the disappearance of 43 student teachers who went missing last September in the southwestern city of Iguala, in Guerrero state.
The Mexican government blamed the abduction on local drug cartels whose hitmen allegedly kidnapped the students as they protested about discriminatory hiring and funding practices in Iguala. The students were reportedly shot or choked to death, their bodies burnt and the ashes thrown into a nearby river.
However, there is speculation that the local police and army were also complicit in the kidnapping, with the victims' families and teacher unions claiming the government was quick to shift the blame to criminal gangs to close the case.
In November, Mexican prosecutors arrested the former mayor of Iguala and his wife. The mayor was charged with complicity in the students' disappearance the month before.
The unions are also concerned about delayed payments to almost 100,000 teachers. In January, teachers from neighboring Oaxaca state occupied an airport there, disrupting flights.