The shooting of the 16-year-old has sparked violent protests and the Roma community says his ethnicity was a factor.

He had been in a critical condition after emergency surgery since the 5 December incident.

A hospital in Thessaloniki, Greece's second-biggest city, said that despite "tireless efforts" the boy died on Tuesday morning.

Antonis Tasios, secretary of the Roma community where the teenager lived, said: "Everyone here is crying. It is unjust for a child to leave like this. We have great pain."

A 34-year-old police officer has been charged with attempted manslaughter and illegally firing his gun.

About 200 people from the Roma community demonstrated outside court when he appeared on Friday.

"It wasn't the petrol, it wasn't the money, the cops shot because he was Roma," people chanted.

Some also burned €20 notes - the same amount as the petrol he's said to have stolen.

Violent protests have spread from Thessaloniki to other areas, such as the capital Athens, with vehicles torched, burning barricades, and petrol bombs thrown at riot police.

The teenager, who hasn't been formally identified, allegedly drove away from a petrol station in his truck without paying and was chased by police on motorbikes.

The arrested officer told the court he fired after the boy tried to ram him three times and because he feared for the lives of his colleagues.

Citizens' Protection Minister Takis Theodorikakos, who presides over Greek police, tweeted his "deep sorrow for the death of the 16-year-old boy" and extended his condolences to the teenager's family.