A fire at a large campsite on the southern shore of Lake Garda in northern Italy has injured at least 20 people and destroyed about 20 holiday units, according to Italian authorities and regional officials. The blaze broke out shortly after 6 a.m. at the Bella Italia campsite in Peschiera del Garda, a town near Verona, as many guests were still asleep.

Casualty figures differ slightly between reports. Italian media cited by Dutch broadcaster NOS said at least 20 people were taken to hospital, one of them reportedly in critical condition. The president of the Veneto region put the number at 24 people hospitalised with burns. Reports also indicated that most of the injured suffered carbon monoxide poisoning from the smoke. The cause of the fire has not been established.

The fire destroyed around 20 mobile homes or bungalows, several cars and part of the surrounding vegetation, according to the fire service. Firefighters were hampered by exploding gas cylinders; LPG bottles, which are commonly used for cooking and heating at campsites, and the presence of vehicles made the blaze harder to contain.

Before the Italian fire brigade arrived, four German volunteer firefighters who were on holiday at the site stepped in. Regional officials said they woke guests, carried gas cylinders to safety, helped to contain the flames and drove an injured person to hospital. The four, who are from Dietzenbach, a town in Germany's Hesse state, had arrived at the campsite only the day before. Regional leaders publicly thanked them for their courage and solidarity.

The campsite is a five-star facility with about 400 pitches and some 1,300 accommodation units, including apartments and mobile homes, which gives an idea of the number of people who could have been at risk. Lake Garda, Italy's largest lake, is one of the country's most popular holiday destinations, drawing large numbers of visitors from Germany, the Netherlands and other European countries, particularly in summer.

Why this matters: campsites with densely packed mobile homes and bottled gas can pose particular challenges when a fire starts, as this incident showed. The authorities have yet to say what caused the blaze, and the condition of the most seriously injured guest remains the main concern.