Thousands of Neapolitans crowded into the city's cathedral yesterday to witness the miracle of Saint Gennaro, whose dried blood is said to liquefy twice a year, 17 centuries after his death.

Cardinal Crescenzio Sepe, archbishop of Naples, announced the blood turned to liquid at 9.45am and the glass phial was paraded to crowds outside, who set off fireworks in celebration.

Legend has it that when Gennaro was beheaded by pgan Romans in 305AD, a Neapolitan woman soaked up his blood with a sponge and preserved it in a phial.

The substance usually turns to liquid twice a year - on September 19, the saint's feast day, and the first Saturday in May. Sceptics say the "miracle" is because chemicals in the phial change viscosity when it is stirred or moved.

Neapolitans fear disaster if it does not liquefy, as in 1980, when an earthquake killed 3000 people.