Panaji, Sep 3 (IANS): The run-up to Goa's tourism season, beginning next month, could not have got off to a worse start.

With slimy tar balls resulting from an oil spill leaving oily scars across beaches over the last few days, several robberies have created fear psychosis among tourists.

A Pune-based tourist couple was robbed at gun-point near their guest house in popular tourist hub Calangute as they were returning from dinner Thursday.

"Two unknown English-speaking people approached them with a gun and threatened to kill them if they did not hand over the cash they were carrying," a police official said.

The tourists shelled out Rs.15,000 in cash. The robbers also took away the scooter, which they had locally hired for holiday, police said.

"No one has been arrested. We are compiling a list of suspects who had earlier used this modus-operandi," a police official said.

Two foreigners and a local man were Aug 25 also robbed at gun-point at Calangute, one of the most popular beach resorts in the state.

The foreigners, a Spaniard and a Hungarian were robbed off Rs.10,000.

Goa's tourism season from October to March, brings in 2.5 million tourists annually, half a million of whom are foreigners. Goa's reputation as a safe tourism destination has, however, has come under cloud, after a string of crimes against foreign tourists, especially women, in recent past.