Homeless West African immigrants stormed the cathedral in Naples on Monday, leading to a nine-hour stand-off with police.
The immigrants, protesting alleged preferential treatment for local residents after a recent fire burned down their homes, burst into the Duomo and staged a sit-in.
A scuffle broke out as police tried to get the immigrants out of the church and three people were briefly detained - two from Cape Verde and one from Ivory Coast.
One of them had to be treated for cuts and bruises.
A spokesman for the immigrant policy office of the leftwing CGIL trade union accused the police of being heavy-handed while a member of the centre-left town council said the police had been ''indiscriminate'' in wielding their batons.
Police sources denied they had been ''over-zealous'' in performing their duty.
After the clashes a stand-off ensued in which police in riot gear ringed the cathedral and immigrants lay down on pews inside, refusing to leave the church if it meant having to be identified.
The immigrants were joined by members of Italy's anticapitalist 'No Global' movement.
A leftwing town councillor slammed Naples Archbishop Crescenzio Sepe for calling the police instead of welcoming the immigrants.
A spokesman for the curia denied calling the police and said the local church was ''always ready to help the downtrodden''.
A member of the Northern League party, which is often accused of being anti-immigrant, slammed the immigrants for stopping church services and pointed out that such an incident would only be possible in countries like Italy where there was religious toleration.
Any foreigner breaking into a mosque would be stoned to death, he said.
The incident came three days after the centre-right government, which includes the Northern League, called a nationwide emergency on immigration.
The immigrants, mainly from Ghana, Ivory Coast and Burkina Faso, are protesting after a fire in a Naples apartment building left them homeless three days ago.
They accuse authorities of ignoring their plight while rehousing the Italians who were living in the building.
The immigrants eventually left the cathedral after Naples Mayor Rosa Russo Iervolino agreed to hear their grievances.
Their sit-in had lasted nine hours.
