Four activists from the Ukrainian women's rights group Femen staged a loud topless protest in St. Peter's Square today while Pope Benedict XVI was conducting the traditional weekly Angelus prayer.

Arriving at the site the four women quickly stripped off their shirts to reveal the words 'In Gay we Trust' painted on their bare chests and started screaming 'Shut Up!' as the Pope was speaking to the crowds of pilgrims gathered to view him at the window of his private apartment overlooking the square.

The protest was quickly interrupted by Italian police who after a struggle managed to carry away the four protesters.

Most in the crowds looked on in shock, but one woman was so enraged by the topless protesters she took to hitting one with her umbrella as she called them: "Devilish and diabolical."

The Vatican has become increasingly vocal against gay marriage and adoptions in recent months. The Pope strongly reaffirmed the Church's opposition to gay marriage in December, saying heterosexual marriage had an indispensable role in society.