Italian police raided suspected anarchists across the country today following the Rome riots.
Homes and youth centres used by extremists in cities including Florence, Palermo and Ancona were targeted.
Six people were detained, along with the seizure of gas masks, ski masks and other gear used by rioters as protection from tear gas and to hide their faces.
Interior Ministry under-secretary Alfredo Mantovano dismissed criticism that police were not tough enough against the several hundred rioters on Saturday who used clubs and sledgehammers to smash bank cash machines and store windows, torched police and private vehicles and hurled rocks. Police battled back with tear gas, water cannon and batons.
Politicians from both the opposition and Premier Silvio Berlusconi's coalition called for a get-tough campaign against so-called "urban guerrillas."
"There was tried and true urban terrorism," Francesco Giro, a Culture Ministry under-secretary said, surveying damage near Rome's St. John Lateran Basilica.
"We need to apply anti-terrorism laws," he said in a call for authorities to launch preventive crackdowns on anarchists and insurrectionists.