The arrested men came from across South Asia

The detentions add to fears that Sri Lanka is becoming a major hub for people smuggling.

The men, mostly from Bangladesh, India and Pakistan, were arrested on Thursday at guest houses at the Mount Lavinia beach resort near the capital, Colombo.

However the police later released most of them because they had valid visas to be in Sri Lanka.

'We can't prosecute'

Police say the men wanted to travel on to Italy and Greece.

"They have come into the country legally, but were apparently trying to leave illegally by boat," a police official said, the AFP news agency reports.

"We know why they are here, but we can't prosecute until they commit an offence."

Most of the men have valid visas and return tickets to their countries of origin.

Only a handful without passports will be charged in court, including one Indian man who was hospitalized after he jumped off a building to evade arrest.

New visa system

A total of 649 people have been arrested in Sri Lanka in July in connection with human trafficking efforts.

Italy has long been a destination for immigrants from Sri Lanka

People smugglers are thought to be exploiting a new visa-on-arrival system for tourists.

The scheme was introduced by the Sri Lankan Government earlier this year to encourage South Asian tourists to visit the island.

But police believe the relaxation of visa requirements has internationalised the trade in people smuggling.

Previously operators, often using modified fishing trawlers, would smuggle Sri Lankans to Europe, Japan or Australia.

But the trade appears to have extended to aspiring immigrants from neighbouring countries.

On Sunday police arrested 114 people from Bangladesh, India and Pakistan in the central Sri Lankan town of Kandy.