An earthquake measuring at least 4.0 magnitude hit the popular Italian tourist island of Ischia, off the coast of Naples, causing several buildings to collapse.

One woman has died and seven people are missing following the quake, police have said.

Giovanni Vittozzi, from the Local Civil Protection Department, said the woman was killed when she was hit by a falling block from a church.

He added officials are investigating reports of another victim.

Television images showed that about six buildings in the town of Casamicciola and a church had collapsed.

The town in the northern part of the island is believed to have been hit the hardest by the quake.

Roberto Calloca, a doctor from the Rizzoli Hospital, told Sky TG24 at least 20 people had been treated for minor injuries.

Most of the hospital has been evacuated except for patients on respirators and people were being treated outside in a makeshift emergency room.

Dr Calloca said the situation was calm and under control.

Italy's national volcanology institute said the quake struck just before 9pm local time, when many people would have been having their evening meal.

The National Institute of Geophysics and Volcanology put the magnitude at 4.0 but both the US Geological Survey and the European quake agency EMSC estimated the magnitude at 4.3.

Civil protection squads were already on the island because of bush fires that have been ravaging the south of Italy recently. More units were making their way from the mainland and crews are checking the condition of damaged buildings.

Helicopters and a ferry boat were also bringing more rescue workers from the mainland.

Pictures posed on social media show residents standing in front of rubble blocking off entire streets.

The earthquake happened during the height of the tourist season.

Casamicciola was the epicentre of an earthquake in 1883 which killed more than 2,000 people.