These incredible pictures show Europe's largest active volcano putting on a rare and spectacular 'smoke ring' display.<br /><br />Holidaymakers caught the moment Mount Etna in Sicily, Italy blew rare volcanic vortex rings into the sky.<br /><br />The phenomenon happens when rings made of vapour are generated by the release of rapid gas and comes after the opening of a new circular crater.<br /><br />The circular rings can be seen in the sky above the tourists and volcano at 1pm in the afternoon.<br /><br />Juliet and Richard, from London, were holidaying in Sicily with their two young sons when they witnessed the rings on April 5.<br /><br />Juliet said: "It was amazing and out of this world. <br /><br />"Our coach driver who took us up the mountain was so excited as he hadn’t seen rings like that for ten years - he said he was going to call it 'Ring Day'.<br /><br />"We knew we were witnessing something special."<br /><br />The volcano Mount Etna sits above the town of Bronte, on Sicily at 11,014 feet and activity had been recorded there for more than 3,500 years.
