Prince George Getting More Security Post-ISIS Threat

The Royal Family isn't taking any chances in wake of the terrorist call to action targeting Prince George ... TMZ has learned he'll be getting added protection at his school and on outings around London.

Sources tell us Thomas's Battersea, George's school in London, will have beefed-up security. More officers will also follow Prince George on outings with his mom and his grandma, Carole Middleton, who often cares for him.

As for this weekend's Trooping the Colour ceremony at Buckingham Palace ... we're told it's business as usual. George will appear with the rest of the family on the Buckingham Palace balcony, but there'll be a bigger security presence than usual.

As we previously reported, the Royal Family is refusing to retreat from the public eye after 32-year-old Husnain Rashid encouraged ISIS to attack the boy at his school.