A magnitude 4.4 earthquake struck the Campi Flegrei volcanic area near Naples shortly before six on Thursday morning, rattling residents from sleep and sending many into the streets. The quake, recorded by the National Institute of Geophysics and Volcanology (INGV) at 5:50 local time, had its epicentre in the sea at a depth of three kilometres, between the coastal towns of Bacoli and Pozzuoli. It was felt across much of the Neapolitan metropolitan area, from the western suburbs to the historic centre and the Vomero hill. No casualties were reported, but local authorities described minor structural damage, including fallen plaster and the partial collapse of a seafront promenade in Bacoli.

This event ranks among the strongest in the current bradyseismic crisis that has gripped the Phlegraean Fields since 2023, exceeded only by the magnitude 4.6 tremor of 30 June last year. Bradyseism – the slow rise and fall of the ground due to hydrothermal pressure – has caused thousands of smaller quakes and persistent uplift. The Thursday morning shock was followed by a seismic swarm, with at least four aftershocks recorded within the first hour, including one of magnitude 2.1. Many residents, drawing comparisons to the violent June 2025 event, described the shaking as prolonged and accompanied by a loud boom.

Municipal authorities acted swiftly. Schools were closed in the towns of Bacoli, Pozzuoli, Quarto, Monte di Procida and Procida, as well as in the Naples districts of Bagnoli and Fuorigrotta, to allow for structural inspections. The mayor of Bacoli, Josi della Ragione, confirmed that technical teams were assessing buildings and urged caution. The INGV’s Osservatorio Vesuviano continued to monitor the swarm, noting that the energy release is consistent with the ongoing deformation of the caldera.

Viewed from the international community, the quake renews attention on one of the world’s most dangerous volcanic systems. The Campi Flegrei caldera, which last erupted in 1538, produced two super-eruptions in prehistory, whose ash reached as far as Russia. Analysts in London and elsewhere note that while scientists do not forecast an imminent eruption, the intensity of the seismic unrest – characterised by accelerating uplift and increasingly frequent magnitude 4 events – is unprecedented in the modern monitoring era. With some 800,000 people living within the caldera, the margin for complacency has shrunk. The coming days will be critical as experts analyse whether this swarm heralds a further escalation or the gradual release of accumulated pressure.