According to a police officer, the protest was triggered______

Hundreds of youths stormed a police station and set fire to cars in southeastern Nigeria on Tuesday after a protester was fatally shot by a police rifle, officials said.
   The youths began protesting Tuesday morning over demands that a local oil refinery and petrochemical plant employ more people from the area, said police chief Samuel Adetuyi.
   They set fire to part of a police station in the Niger delta village of Ogale and burned an SUV in its courtyard. One protester was killed when he tried to grab a rifle from a police officer and the gun accidentally went off, he said.
   Discontent is high among people in the Niger delta over unemployment and continued poverty despite booming oil production in their area.
   Nigeria is the world’s seventh largest oil exporter and the fifth largest supplier of crude oil to the United States.