CAIRO, July 11 (Reuters) - Islamic State claimed responsibility for a car bomb attack at the Italian consulate in Cairo on Saturday, in an escalation of a Sinai-based insurgency that suggests militants are opening a new front against foreigners in Egypt.

"Through God's blessing, Islamic State soldiers were able to detonate a parked car bomb carrying 450 kg of explosive material on the headquarters of the Italian consulate in central Cairo," the group said on its Twitter account.

"We recommend that Muslims stay clear of these security dens because they are legitimate targets for the mujahideen's strikes." (Reporting by Cairo bureau; Writing by Michael Georgy; Editing by Robin Pomeroy)