Police in Saudi Arabia have fired on protesters and launched stun grenades at them in the Shiite-dominated city of Qatif, according to the Associated Press.

The several hundred strong protestors were marching in the city’s streets. AP’s source said he saw at least one protestor get injured from police fire. 

The minority Shiite population, responsible for much of the unrest in Saudi Arabia lately, alleges discrimination against them on the part of the Sunni government.   

Saudi government officials have maintained that protests are illegal. An earlier report from AP said the police opened fired after the government warned it won’t tolerate protests.

Today’s events come before Friday, dubbed the “Day of Rage,” as various opposition groups have planned protests for that day after prayers.