Hundreds of Muslims marched through central Athens on Thursday, damaging shops and cars, to protest what they said was the destruction of a copy of the Quran by a Greek policeman.
The president of the Muslim Union of Greece, Naim Elghandour, said that during police checks at a Syrian-owned coffee shop on Wednesday, an officer took a customer's Quran, tore it up, threw it on the floor and stomped on it.
In response, about 1,000 immigrants, many from Syria, Pakistan and Afghanistan, marched to central Omonia Square, smashing several shop windows and five cars, a police official said.
Police sources said an internal investigation was launched into the Quran incident.
"We were told by police we will be given the name of the policeman who did this so we can press charges," Elghandour said.
Immigrants rights groups have called another protest for Friday.
Thousands of immigrants, many from Muslim countries, cross into Greece illegally every year seeking a better life in the West. Trapped in legal limbo, most have no jobs, live in squalid conditions and are often arrested for minor crimes.
On May 9, members of a rightist group attacked immigrants in Athens, sending at least three to hospital. Rights groups accuse predominantly Orthodox Christian Greece of not doing enough to protect immigrants.