The Australian government has sent another group of people who arrived by boat back to Sri Lanka in a tough move designed to deter further arrivals.

The latest group, comprising 30 single adult men, were returned involuntarily on a charter flight to Colombo from Christmas Island today.

The men had arrived on a number of boats in recent days.

Immigration Minister Chris Bowen said the men ''raised no issues that engaged Australia's international obligations''. ''They were advised of their status and that they were subject to removal from Australia,'' Mr Bowen said in a statement.

''Without a valid visa they had no legal right to remain in Australia and were removed at the earliest opportunity.''  Mr Bowen said people returned involuntarily received no reintegration assistance.

Since August 13, when the government's offshore processing regime started, 156 Sri Lankans have returned to Sri Lanka either voluntarily or involuntarily.

Last week, the government returned 27 Sri Lankans on two flights. The previous Saturday, it sent back 14 Sri Lankans who arrived on a fishing trawler that had allegedly been hijacked in Sri Lankan waters.

Mr Bowen has defended its actions by saying the government was sending a message that it would not accept ''economic refugees''.

''We will not have people that do not have genuine claims to make going through our system,'' he said last week.

The tough line has been applauded by the Coalition but criticised by the Greens.

The lastest removals come as Australia has told Sri Lanka that it must stop its police and army abusing, torturing and mistreating its citizens, and must end the disappearances and abductions occurring across the country.

Australia's demands to Sri Lanka were made in Geneva as part of the United Nations universal periodic review process, in which all UN countries have their human rights records assessed by fellow members.

In July, Fairfax revealed that asylum seekers forcibly returned to Sri Lanka had faced arbitrary imprisonment, torture and harassment by security forces.(smh.com)