Since Monday night, "about 150 earthquakes have been recorded" in the volcanic area of the Phlegraean Fields (south), the National Institute of Geophysics and Volcanology (INGV) reported today in a statement quoted by the French agency AFP. The largest of the earthquakes had a magnitude of 4.4, very noticeable because it occurred at a shallow depth, 2.6 kilometers below the Phlegraean Fields, an area with about half a million inhabitants. Civil Protection activated the Crisis Unit in Naples and in the neighboring cities of Pozzuoli and Bacoli, which are located in the volcanic caldera of the Phlegraean Fields, which has recently recorded constant seismic activity. Many inhabitants of Pozzuoli, a municipality in the area of activity of the Phlegraean Fields, fled their homes following the tremors, which caused minor damage to buildings, but no victims. "This will be a night we will not forget," wrote the Mayor of Pozzuoli, Gigi Manzoni, on social media, according to the French agency AFP. Amateur videos showed the floor of a supermarket in Pozzuoli full of bottles that fell from the shelves due to the earthquakes. Four reception centers were opened for residents seeking shelter to spend the night, while schools will be inspected by firefighters. The Naples emergency coordination center mobilized 400 camp beds in Pozzuoli, where tents were set up, and in Bacoli. The volcano, which extends over a perimeter of 15 by 12 kilometers, presents the typical flat-bottomed depression left after an eruption. It is the largest active caldera in Europe, located on the seashore between Naples and Pozzuoli. In this region, the Phlegraean Fields are overshadowed by the neighboring Vesuvius, which dominates the Bay of Naples and whose eruption wiped Pompeii off the map in 79 AD. The Phlegraean Fields erupted 40,000 years ago and affected the planet's climate. The volcano worries inhabitants and scientists due to a resurgence of activity caused by gases emitted by magma, which put pressure on the surface and open fissures in the ground. According to INGV, the speed at which the ground has been rising, two centimeters per month, has not changed so far. "During the seismic crisis of 1982-84, the ground was rising at a rate of nine centimeters per month," said the institute. At that time, "more than 1,300 shocks were recorded per month, of which 450 in the last month," he added. Read Also: Generali's profit falls 9% in the 1st quarter to 1,119 million euros (Portuguese version)