Il Nuovo Postiglione - Rome's ancient Arch of Constantine damaged by lightning

"All the fragments were recovered and made safe" following the strike on Tuesday afternoon, a spokeswoman for the Colosseum archaeological park told AFP.

"Damage assessments have already begun and analyses are continuing this morning with a works site already operational," she added.

The arch, built in 315 to celebrate the victory of Emperor Constantine in the battle of Ponte Milvio, was already undergoing maintenance work, which had begun on Monday.

Standing about 25 metres high, it is the largest of the three triumphal arches still preserved in Rome. It is located along the route followed by triumphal processions, near the Colosseum.

After a hot, dry summer, the centre of Rome was hit on Tuesday afternoon by a sudden storm, bringing heavy rain, high winds, thunder and lightning.

More than 80 millimetres (3.1 inches) of rain per square metre fell on the historic centre -- about the same amount that falls on average in a month in autumn, the municipality said.

The "downburst" caused floods and winds of up to 90 kilometres per hour (56mph) that brought down trees, it said.

Experts say climate change is shifting weather patterns and increasing the number of extreme weather events.

"It is increasingly evident that the issue of climate change and its impact on our lives is now unavoidable for everyone," said Rome mayor Roberto Gualtieri.

M.Costa--INP