Authorities in Mexico say a tanker truck carrying tar has slammed into a highway toll booth that had temporarily been taken over by protesting teachers.
They say seven people are dead and another 14 injured.
Most of the dead and injured are believed to be teachers who have been holding a series of protests in the western state of Michoacan.
State prosecutors' spokesman Alejandro Arellano said the accident occurred Thursday (today, NZ time) on a highway west of the state capital city of Morelia.
The teachers are protesting educational reforms that would reduce union power in hiring decisions and establish teacher evaluations.
Protesters in Mexico often seize highway toll booths, and sometimes demand drivers pay a small sum to drive through without paying a toll.