The mayor said the attack had given Naples a bad name

The tourist, Matthew Godfrey, 25, from Utah, was attacked, after trying to pursue two men who stole his camera and fled on a scooter.

Instead of helping him, a group of bystanders punched and kicked him, allowing the muggers to escape.

The mayor, Rosa Russo Jervolino, said the action of the locals in protecting the muggers tarnished the city's name.

The police took Mr Godfrey to hospital where he was treated and released and subsequently left Naples.

I have officially invited Matthew... to return to Naples soon to eat a pizza together Leonardo Impegno, Local council

The police have arrested the two suspected thieves, acting on Mr Godfrey's description of them, and are trying to identify the people who took part in the assault.

In her apology, the mayor said the attack was "inexcusable" and had given Naples an "uncivilised image".

The head of the local council also condemned the behaviour of the local residents and offered Mr Godfrey a personal tour of the southern Italian city.

"I have officially invited Matthew, who in the meantime has left to continue his travels, to return to Naples soon to eat a pizza together," Leonardo Impegno said in a statement, quoted by Reuters news agency.