Turkey braces itself for more protests as the funeral for a teenage boy injured during last year's anti-government protests is due to take place in Istanbul.

The 15-year-old, Berkin Elvan was walking to buy bread when he was struck in the head by a tear gas canister during the unrest in the city in June.

Turkish riot police fired tear gas at nearly 1,000 protesters on Tuesday who gathered outside the hospital in Istanbul where Elvan died.

The story of Elvan, who spent 269 days in a coma, gripped the nation and became a symbol of the heavy-handed tactics used by police to reign in the biggest demonstrations that Prime Minister Recep Tayyip Erdogan had faced since coming to power in 2003.

Police used tear gas and water cannon after several dozen protesters hurled stones at a police bus and stole helmets and shields, an AFP photographer said, adding that one demonstrator was injured.

Human Rights Watch charged that police violence against demonstrators was an "endemic problem" in Turkey.

Protests last year started as a small environmentalist movement to save an Istanbul park from being razed, but snowballed into a nation-wide wave of protests against Erdogan, who critics say had become increasingly authoritarian.

Elvan's death brought the toll from the unrest to at least eight, including a policeman.