At least nine people were injured, one in critical condition, when the terrace of a restaurant collapsed Monday evening in St Julian's, Malta's most bustling tourist town.

Forty people were having dinner at the extended terrace of Barracuda restaurant overlooking the Mediterranean Sea at around 20:10 (1810 GMT) when it collapsed onto the terrace of Piccolo Padre Pizzeria one floor lower.

Nobody was on the Piccolo Padre balcony at the time. One person was seriously injured in the accident, Maltese Minister for Health Chris Fearne said in a tweet.

Eyewitnesses inside the restaurant described hearing "unusual roar" when the accident happened.

Police and other emergency services including the Armed Forces of Malta patrol boats carried out a rescue operation.

The family-run Barracuda restaurant which specializes in seafood has been operated in Maltese islands for the past 36 years.