He denounced the violence as "against human rights" and defended the police response saying that "no rage, even justified, must lead to protests like those we saw yesterday [Saturday]".

Barnaby Phillips, Al Jazeera's correspondent in Athens, said local "people are shocked by the extent and ferocity of the violence".

He said that the political fallout from the rioting would become clear in the coming days.

Resignation

Pavlopoulos said he had offered his resignation but it had been rejected by Costas Karamanlis, the Greek  prime minister.

The riots will increase pressure on the already fragile Greek government [Reuters]
Emergency services tackled blazes in 16 banks, about 20 shops and more than a dozen cars in Athens alone.

Police officials declined to release figures for the number of people injured or arrested. 

The teenager whose death sparked the violence was rushed to a nearby hospital where he was confirmed dead.

The news enraged hundreds of youths in the neighbourhood, who began attacking police cars with stones and firebombs, burning dozens of cars and smashing shop windows.

"Hundreds of them hit the streets, probably for revenge ... Dozens of police units are gathering to try to control the situation," a police official, who declined to be named, said.

Tear gas

Police responded by firing tear gas at the crowd, evacuating some restaurants in the area, and closing several streets to all traffic.

Calm had been restored to Athens on Sunday, although barricades erected by protesters and charred vehicles remained on some streets, while broken bottles and rocks littered main streets.

Left-wing groups have called for further protests to be held later on Sunday in Athens.

Separately, police sources said that two police officers had been arrested and were being questioned over the incident.

Karamanlis's fragile government has lost three ministers to scandals in the last 12 months alone.