ATHENS (Reuters) - Greek police arrested a 33-year old Serb on Tuesday over the murder of a young American tourist on the Greek island of Zakynthos last week, bringing the number of people detained in the case to nine.

The 22-year old tourist was beaten to death early on Friday outside a bar at Zakynthos’ resort of Laganas, known for its rowdy nightlife.

The arrested man will appear before a prosecutor later this week.

Six Serbs, one Greek and a British national were arrested last week and have been charged with murder. They were expected to respond to the accusations on Tuesday but the hearing was postponed for later this week.

The incident has shocked Greece, which is relying heavily on tourism to help it emerge from its debt and austerity crisis and is visited by about 25 million holidaymakers a year.

Greece has in recent years vowed to crack down on crime at coastal resorts which have become notorious for violence or indecency among drunken young holidaymakers.

In 2008, a young Australian man was left brain dead by a beating from nightclub workers on the island of Mykonos. An 18-year-old Briton was stabbed to death in Laganas in 2011.