Italy has beefed up security at "sensitive targets" after the attack on the French satirical newspaper Charlie Hebdo, citing the presence of the Vatican and Italy's participation in anti-terrorism coalitions.

Interior Minister Angelino Alfano said Wednesday there were no concrete threats about any possible attacks here, according to the ANSA news agency.

But he said security was reinforced around "sensitive" French, U.S. and Jewish targets. He noted that the Islamic State group has boasted it aimed to conquer Rome — the seat of Christianity.

Pope Francis strongly condemned the attack as "abominable," saying such violence is never justified.

A solidarity rally by the Italian journalists' union was planned for Thursday in front of the French Embassy.