Italian police have arrested 142 people in the course of a two-day security operation in and around Milan which was prompted by the London bombings.
Italy has boosted anti-terror measures after the London attacks
Most were detained over drugs, theft or illegal immigration while 1.5 kilos (3.3 pounds) of explosives were found at the home of a convicted criminal.
Some 2,000 police took part in the operation in Italy's business capital.
Threats have been posted on Islamist websites threatening to attack the country, which has troops in Iraq.
A police official, Col Cosimo Piccino, said the sweep was meant "to guarantee greater security after the London attacks and to combat illegal immigration and street crime".
Some 7,000 people are said to have undergone preventive police checks.
Police reportedly raided several Gypsy camps and other deprived areas.
Of those arrested, 83 are said to be non-EU citizens. Deportation orders have already been issued for 52 of them.
"Charges are mainly related to crimes like burglary, theft, evading home arrest and infringement of drug laws," Col Piccino was reported by daily Corriere della Sera as saying after the arrests.
In a separate development, police evacuated part of Rome's Fiumicino airport after a false alarm sparked by an unattended bag earlier this morning.
Speaking from the G8 meeting in Gleneagles, Italian Prime Minister Silvio Berlusconi said Italy would start withdrawing 300 troops from Iraq in September.
But he underlined that the partial pullout had already been announced and that Italy's presence in the region would continue until the Iraqi authorities will be able to replace it with their own security forces.
"Commitments must be met," he said.