FIVE people were arrested in London by Scotland Yard detectives investigating a potential threat to the Pope, sources said.

Addressing a crowd of about 4,000 youngsters at St Mary’s, the Pope warned against the limitations of both celebrity and science.

He said: “Young people are often encouraged to model themselves on figures from the world of sport and entertainment.

“My question for you is this: What are the qualities you see in others that you would most like to have yourselves? What kind of person would you really like to be?’

“I’m asking you not to be content with second-best.”

He said having money or a successful career was not enough to make people happy.

He said: “Happiness is something we all want but one of the great tragedies of this world is that many people never find it because they look for it in the wrong places.

“The key to it is very simple - true happiness is to be found in God.”

He continued: “Always remember that every subject you study is part of a bigger picture. Never allow yourselves to become narrow.

“The world needs good scientists but a scientific outlook becomes dangerous and narrow if it ignores the religious or ethical dimensions of life, just as religion becomes narrow if it rejects the legitimate contribution of science to our understanding of the world.”