ERFURT, Germany (AP) _ Police have detained a teen-ager with ties to the extreme right as a suspect in an attempted arson attack on a synagogue in eastern Germany, authorities said Monday.

The 18-year-old was on probation after convictions for displaying neo-Nazi symbols and bodily assault, Thuringia state Interior Minister Christian Koeckert said.

He was carrying a membership card from the extreme-right National Democratic Party of Germany, but under initial questioning denied involvement in the attack, Koeckert said.

A Molotov cocktail filled with diesel fuel was thrown at the small synagogue Thursday night just after Passover celebrations, but it failed to ignite after the wick fell out. The building was undamaged.

Investigators believe the teen-ager was not acting alone and are searching for further suspects, Koeckert said. Authorities did not release the suspect's name, which is common in Germany until formal charges are filed.

The suspect was identified from fingerprints on a letter found near the synagogue that claimed responsibility in the name of a previously unknown group, Koeckert said.

The note, which ended with ``Heil Hitler,'' was signed ``Die Scheiteltraeger,'' or ``the side-part wearers,'' a reference to Adolf Hitler's severe haircut.

The attack came on Adolf Hitler's birthday, often a rallying point for neo-Nazis. Local authorities offered a $5,000 reward for help in solving the crime.

It was believed to be the first such attack in Germany since neo-Nazis set a synagogue in Luebeck ablaze in 1994 and again in 1995.

Germans laid flowers and held vigils over the Easter weekend outside the Erfurt synagogue, built in 1952 to replace one destroyed by the Nazis.

``It's comforting to receive such a show of solidarity,'' said the head of Thuringia's 600-strong Jewish community, Wolfgang Nossen. ``But I would like it more if we didn't need such sympathy. We want to live in this city as normal citizens.''

Thuringia is an economically depressed state of 2.5 million in former communist East Germany, an area with unemployment of 20 percent or more that has become a hotbed of neo-Nazi crime since the fall of the Iron Curtain.

In the latest incident, four Germans beat a 22-year-old Turk after chasing him through the center of Erfurt Sunday night, police said. The Turk escaped after slashing one of his attackers with a knife.

There was similar violence elsewhere in Europe.

Greek police promised heightened security at Jewish sites Monday after vandals painted swastikas on a synagogue and targeted a Holocaust memorial for Greek Jews in a Passover attack in the port city of Thessaloniki. A red swastika was sprayed on the synagogue door along with the German word ``Raus'' _ meaning ``out.''