Turkish prosecutors have completed a first batch of indictments in a graft scandal that has rocked the 11-year rule of Prime Minister Recep Tayyip Erdogan, overcoming intense pressure from his conservative government, local media reported Friday.

Mustafa Demir, the mayor of Istanbul's Fatih district, a stronghold of Erdogan's Justice and Development Party (AKP), is among 21 people in the indictment, the reports said, without naming the others.

Riot police fired tear gas and water cannon at protesters in Ankara and Istanbul on Wednesday as tens of thousands took to the streets to mourn a teenage boy who died from injuries suffered in last year's anti-government protests.

In the Turkish capital, police clashed with demonstrators as they tried to stop traffic, making a number of arrests and leaving several injured.

Turkish riot police fired tear gas Tuesday at protesters massed outside a hospital after the death of a teenage boy wounded during anti-government protests last year and left comatose.

About 1,000 people staged a rally outside an Istanbul hospital in solidarity with 15-year-old Berkin Elvan, who 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.

Turkey vowed Tuesday to press ahead with the construction of what could become one of the world's busiest airports despite a court order halting work.

A court last month suspended work on Istanbul's third airport after local residents and environmental groups filed a lawsuit, arguing that the operations caused serious damage to the environment, the Hurriyet newspaper reported.

Four Turkish policemen on Monday denied beating to death a 19-year-old student in mass anti-government protests that rocked the country last June, as they went on trial amid heavy security.

The high-profile murder case comes as Prime Minister Recep Tayyip Erdogan battles his biggest political crisis in 11 years in power, which has hit the economy and is threatening the strongman's presidential ambitions.

Turkish riot police were out in force on Sunday as large crowds massed in Istanbul to demand justice for a prominent Turkish Armenian journalist murdered seven years ago.

"Murderer state will account for this," chanted several thousand protesters gathered in Istanbul's Taksim Square to mark the anniversary of Hrant Dink's killing, with questions still lingering about the circumstances of his death.

Turkish prosecutors said Friday they have charged 36 protesters with terrorism over mass anti-government demonstrations that swept the country last year.

They face a range of charges including being a member of a terrorist organization, illegal possession of hazardous material and terrorist propaganda, Hurriyet newspaper reported, quoting the indictment.

Around 1,000 protesters flooded an Istanbul metro station on Tuesday after a young homeless man was reportedly beaten by a security guard when he tried to board without paying.

The demonstration flared into a broader protest against the government, which has been battling a damaging political crisis sparked by a corruption probe.

The Istanbul police chief has been dismissed after dozens of people including the sons of cabinet ministers were detained in a sweeping graft probe, media reports said Thursday.

Huseyin Capkin, who had been at his post since June 2009, is the latest of 30 senior police officers to be sacked in Istanbul and Ankara for "abusing their power".

Five Turkish police chiefs have been dismissed after dozens of people including sons of cabinet ministers were detained in a high-profile probe into bribery and fraud, media reports said Wednesday.

The police raids on Tuesday and the subsequent sackings have highlighted deep rifts in Prime Minister Recep Tayyip Erdogan's support base ahead of key elections in Turkey next year.