(CNN) -- Hundreds of Palestinians gathered in the West Bank Sunday to mourn the death of a Palestinian activist who died after being hit in the face by what appeared to be an Israeli military-fired tear-gas canister.
The body of 28-year-old Mustafa Tamimi was carried in a procession that began in the West Bank capitol of Ramallah ending 10 kilometers north in his home village of Nabi Saleh.
Tamimi was among dozens of protesters who gathered in Nabi Saleh Friday for a weekly demonstration protesting what residents say is the encroachment of a nearby Israeli settlement.
The protest turned violent, with protestors and soldiers exchanging volleys of rocks and tear gas.
During the fighting, according to protest organizer Jonathan Pollak, Tamimi was hit in the face at close range with a tear-gas projectile fired by an Israeli soldier.
Tamimi was critically wounded and brought to an Israeli hospital for emergency treatment.
A photograph of the incident appears to show a projectile fired in Tamimi's direction from the back of an Israeli military vehicle.
Tamimi's death and the photo capturing the purported moment before he was hit have renewed concerns about the Israeli military's use of force in dealing with Palestinian demonstrators, and raised questions from human-rights groups as to whether military rules of engagement are being followed.
"The main problem we identified with the use of these weapons is that very often there is a common practice of using them unlawfully," said Sarit Michaeli, the communications director for Israeli human-rights group B'tselem. "When soldiers fire tear-gas canisters directly at people they are not only violating the army regulations, they are also using these weapons in a way that is extremely dangerous."
Michaeli says over the course of the past eight years, 20 people have been killed participating in demonstrations for Palestinians.
In a statement released Sunday, the Israeli military said "several hundred Palestinians began rioting " near the Israeli settlement of Halamish "and threw rocks at security forces who responded with non-lethal riot dispersal means...initial investigations indicate that Tamimi threw rocks at IDF soldiers."
Israeli military spokeswoman Lt. Col. Avital Leibovich told CNN the incident was under investigation but that it could be a number of weeks before preliminary findings are released.
CNN's Kareem Khadder reported from Nabi Saleh, West Bank, for this story.