Germany - Two suspects held in Germany in connection with the right-wing stabbing of a police chief were released Tuesday, with police saying there was no evidence against them.

Alois Mannichl, 52, chief of police in the southern city of Passau, says he was knifed by a shaven-headed, tattooed man on December 13 at the door of his home. Mannichl survived.

The attack raised fears in Germany that neo-Nazis are turning

violent, but the assailant, who yelled rightist abuse, has not been caught. So far four suspects have been detained, but all released.

In Passau, a police spokesman said a man, 33, and a woman, 22, from Munich had been under suspicion as accessories, but no evidence had been found against them or any of their neo-Nazi friends.

Earlier, two Passau rightists were held, but released after Mannichl was shown their photographs. He said neither was the assailant. Since then wanted posters have been issued, using drawings of two men from Mannichl's descriptions.

Those drawings show men with unusual tattoos on their scalps, but police say the have no firm evidence of the assailant's identity. Police say it is possible the drawings show one and the same man.

On Monday evening, 500 people gathered in the rain on the market square of Fuerstenzell, the Passau suburb where Mannichl lives, for a candlelight vigil to denounce the neo-Nazis.

Leaving hospital last week, Mannichl said he would not be intimidated and vowed to continue fighting right-wing extremists. Overt neo-Nazi campaigning is a crime in Germany.

He has been vilified on websites popular with neo-Nazis after the rightists put a Nazi flag on a sympathizer's coffin before burial in a Passau cemetery. Mannichl ordered the grave dug up to seize the flag as evidence.

One of Germany's police unions, DPG, appealed Tuesday for 500 extra police to be hired to "patrol" the internet, reading neo-Nazi websites to uncover neo-Nazi intentions and gather evidence of hate speech. (dpa)