The cities are home to large Turkish communities, part of the 2.4 million people of Turkish origin who live in Germany.

Marchers chanted slogans against the outlawed Kurdish Workers Party (PKK) and carried banners reading, "Peace at Home, Peace Throughout the World" and "Together Against Terrorism."

Many of the protesters condemned the PKK for launching attacks against Turkish forces from bases in northern Iraq, prompting fears that Ankara would invade its neighbor.

"We are deeply concerned about the incidents in Turkey," said Rahmi Turan, who organized the rally on behalf of the Turkish Initiative Against Terrorism.

No violence was reported by late afternoon. A protest by Turks and Kurds in Berlin two weeks ago turned violent, resulting in injuries to 18 policemen and eight arrests.

On November 3 more than 10,000 Turks and Kurds held demonstrations in three German cities against the violence in their country.

Tensions constant on Turkish-Iraq border

Turkey has threatened military action against PKK bases in northern Iraq and has accused the Iraqi Kurds there of tolerating and aiding the PKK.

Tensions along the Turkish-Iraqi border increased after October 21, when PKK militants ambushed a military unit, killing 12 soldiers and capturing eight. The captives have since been released.

The PKK, listed as a terrorist group by Ankara and much of the international community, has waged a 23-year armed campaign for Kurdish self-rule in Turkey's southeast. The conflict has claimed more than 37,000 lives.

The PKK is seeking wide-ranging autonomy for the predominantly Kurdish provinces in the south of Turkey.