OAXACA, Mexico – One person died and eight were injured when a car transporting fireworks and gasoline for use in making Molotov cocktails exploded in the southern Mexican city of Oaxaca during violence on the third anniversary of the six-month revolt here in 2006, union officials said on Sunday.

The dead man is the caretaker of a hotel who was transporting the materials in a truck for the protest march planned to commemorate the anniversary of the protests three years ago.

The violence erupted on June 14, 2006, after police tried to dislodge protesting teachers and led to six months of tension and revolt in the city in which the demonstrators demanded the resignation of Gov. Ulises Ruiz.

Along with the man who died on Sunday, eight other people were seriously injured, all of whom worked for the teachers union – which, along with assorted social sectors, had staged the revolt – and they were taken to the local hospital.

The explosion came minutes before the start of the march, which had attracted tens of thousands of people, was about to start out from the outskirts of the city en route to the central plaza, or Zocalo.

After the incident, the hotel owner was taken to the hospital, but he died in the ambulance.

The head of the local section of the SNTE educational workers union, Azael Santiago Chepi, did not rule out the possibility that the blast could have been the result of an attack.

The disturbances on Sunday, 21 days prior to the elections for the federal lawmakers and local officials, mirror what occurred in 2006 with barricades erected around the city, protesters throwing Molotov cocktails, vandalism at bank offices and buses taken over to use to block traffic.

The barricades were placed at spots where murders occurred three years ago, including the site where U.S. cameraman Bradley Will was killed and in front of the radio station where activist Lorenzo San Pablo was shot.

During the six months that the revolt lasted, there were about 20 people killed and dozens injured and arrested.