.

Some windows of the French Institute, a cultural and educational center, were smashed but the interior was not seriously damaged in the attack by about 20 people, police said. A nearby bank ATM was also damaged, but nobody was injured.

"Spark in Athens. Fire in Paris. Insurrection is coming," read one slogan spray-painted onto the building's walls in French. Another, written in Greek, read "France, Greece, uprising everywhere."

The French ambassador to Greece. Christophe Farnaud, who visited institute, said French cultural institutions in Greece would be closed temporarily "as a precaution."

Athens has seen near daily hit-and-run attacks by youths throwing firebombs in the past two weeks, after the fatal police shooting of a 15-year-old boy sparked the worst riots Greece has seen in decades. The rage unleashed by the Dec. 6 shooting has lifted the lid on years of dissatisfaction over social inequality, poor employment prospects for young people and increasing anger with the conservative government's economic policies.

In western Athens, some 1,500 people held a peaceful protest against a separate shooting in which police say an unknown gunman shot a 16-year-old boy in the wrist late Wednesday.

"This is an answer to state repression," said one demonstrator, university student Dimitris Andriotis. "We will not stop coming out into the streets until our demands are met."

In contrast to Thursday's riots, central Athens was calm Friday, with crowds of Christmas shoppers out and men in Santa Claus suits holding ponies for children to be photographed on.

Greece's two largest umbrella trade union organizations were to rally later in the day to protest the government's 2009 budget, and professors also planned to protest outside Parliament on education issues.

Students also planned a mass concert Friday in central Athens to support the youthful uprising against "state repression."

On Thursday, a demonstration in central Athens against police brutality by 7,000 students and teachers turned violent, sending Christmas shoppers and panicked families fleeing to safety. Around 200 youths wearing masks hurled firebombs and chunks of marble at riot police, who responded with stun grenades and acrid tear gas.

Mothers snatched children from a carousel in the main square. Waiters stumbled from cafes, choking on the tear gas. Rioters tried to burn the capital's latest Christmas tree, just days after it replaced another tree that had been burned.

Athens police say more than 300 have been arrested in the violence so far.

The two policemen involved in the shooting death of 15-year-old Alexandros Grigoropoulos have been jailed pending trial. One has been charged with murder and the other as an accomplice.

After two weeks of riots, a slogan spray-painted outside the Bank of Greece summed up the mood: "Merry crisis and a happy new fear."