The United Nations has slammed as a possible breach of the Refugee Convention the Australian government’s plans to speedily send a group of Sri Lankan asylum seekers home.

The boatload of asylum seekers believed to be from Sri Lanka arrived at the far-flung Australian territory of Cocos Islands on Thursday - the first such group for months.

At his weekly border protection briefing on Friday, Immigration Minister Scott Morrison refused to confirm where the asylum seekers had come from, but said Sri Lankans could expect ‘‘even more stringent’’ screening than people from other countries.

‘‘Anyone who may have come from Sri Lanka should know that they will go back to Sri Lanka. We have an arrangement with the Sri Lankan government and … we’ll be ensuring that we maximise those who go back and, preferably, they will all go back.’’

Under a deal with the Sri Lankan government struck under Labor, Australia can use ‘‘enhanced screening’’ for people from that country claiming asylum and return them directly. The Coalition wants to take that further and stop boats with Sri Lankans in international waters, then fly them straight home.

The people who arrived on Thursday will be taken to Christmas Island for screening.

A spokesman for the Canberra office of the United Nations High Commissioner for Refugees said fast-tracking or cutting short the assessment of people’s asylum claims could well breach the Refugee Convention.

‘‘Any interception and pre-emptive return of people seeking asylum that is carried out without an appropriate assessment of individual protection needs raises very serious issues over compliance with the Refugee Convention, particularly article 33.1,’’ he said.

While Australia says the end of the civil war in Sri Lanka has meant Tamils from that country no longer need to seek asylum, some human rights groups say there are ongoing human rights abuses there.

At the weekly briefing, Australian Federal Police Commissioner Tony Negus said that since the election, Indonesian authorities had stopped 550 asylum seekers getting on boats and had issued an arrest warrant for ‘‘a very significant people smuggler’’.

Authorities had also arrested eight people linked to people-smuggling, including three high-priority targets. - The Age