An explosion apparently caused by a gas leak ripped through a crowded disco in central Italy Friday night, killing one woman and wounding about 30 people, police said.

The explosion took place shortly before midnight in the women's restroom of the Discoteque Principe, in this Tuscan city 82 miles north of Rome.There were about 600 people in the nightclub at the time of the blast, and it caused widespread panic, according to witnesses.

Police investigators said a gas leak appeared to be the cause, and no trace of an explosive has been found. "It was not a bomb," said a police spokesman.