No reports of damage or injuries as civil protection convenes emergency crisis unit.Southern regions of Italy were jolted awake in the early hours of Tuesday 2 June, a national holiday for the Festa della Repubblica, after a powerful earthquake struck off the Tyrrhenian coast of Calabria just after midnight.  The quake, registered as 6.1 magnitude by Italy's National Institute of Geophysics and Volcanology (INGV), struck at 00.12 Italian time with its epicentre in the sea about 20 kilometres from the north-western Calabrian coast, near Amantea in the province of Cosenza.   The hypocentre was located at a particularly deep 250 kilometres below the seabed. According to INGV, deep earthquakes of this kind are characteristic of the southern Tyrrhenian Sea and are caused by the geological process of subduction of the Ionian lithosphere beneath Calabria. Impact In addition to Calabria, the tremor was felt widely across the Mezzogiorno, including in Naples and Basilicata as well as in Puglia and Sicily.   Despite the considerable magnitude, the combination of the offshore epicentre and the exceptional depth of the hypocentre limited surface impact. The civil protection authority reported no damage to persons or property. Response Following the quake, Italy's national civil protection department said its Sala Situazione (situation room) was in contact with civil protection authorities on the ground, noting that verifications were under way. Department head Fabio Ciciliano convened the crisis unit in Rome at 01.00 to monitor the situation.   The regional civil protection operations room contacted all mayors of the municipalities closest to the epicentre, including Cetraro, Lamezia Terme and Amantea, with no damage reported. The mayor of Cosenza, Franz Caruso, also confirmed the situation was under control.   The north-western Calabrian coast remains one of Italy's most closely monitored seismic zones.   Checks on infrastructure and buildings along the Tyrrhenian coastline were continuing on Tuesday morning.