Storm wreaked havoc in Rome on Tuesday.

Rome's ancient Arch of Constantine near the Colosseum was damaged by lightning during a violent storm that wreaked havoc on the Italian capital on Tuesday afternoon.

The lightning struck the southern side of the fourth-century landmark, where conservation work is already getting underway, causing fragments of the monument to detach and fall to the ground.

In a statement to Reuters on Tuesday, the Parco archeologico del Colosseo said that all fragments were recovered immediately and that assessment of the damage had already begun.

The 25-metre high arch was commissioned by the Roman senate to commemorate Constantine's victory over Maxentius at the Battle of Ponte Milvio in 312 AD.

The Colosseum archaeological park said that checks would continue on Wednesday morning and that the conservation work underway would now also focus on repairing the damage to the monumental arch.

The unexpectedly severe storm, described by Rome's mayor Roberto Gualtieri as a "downburst", saw about a month's worth of rain fall in a few hours, with winds of up to 90 km/h.

The extreme weather flooded streets and led to the closure of two Metro A stations - Lepanto and Manzoni - as well as felling several large trees in the Circus Maximus area.