Police searching for a group of illegal immigrants who escaped from a remote detention centre in South Australia say they have caught another 14, leaving 10 still at large.

There are now growing fears for the health of the remaining eight men and two boys - as temperatures in the surrounding desert have dipped below freezing during the nights.

None of those found so far are any the worse for their ordeal, just a bit cold and hungry

Police spokesman

However, the authorities say it is possible the escapees have already left the region, aided by pro-refugee activists who helped them break out on Thursday.

Police have now scaled down their search and are now only investigating suspected sightings of the immigrants.

"They can't keep helicopters up this long," police spokesman Colin Haigh said.

Hunger strike

The latest dozen captures took place after a tip-off from residents in Port Augusta, 150 kilometres (93 miles) south of the detention camp.

"None of those found so far are any the worse for their ordeal, just a bit cold and hungry," a police spokesman said.

Immigration officials have said all of those who escaped - 28 Afghans, six Iranians and one Iraqi - had had their visa applications rejected.

Meanwhile detainees inside the camp are continuing a hunger strike for an eighth day.

About 100 of the 210 detainees at Woomera, including five children, are refusing to eat.

Jail threat

Woomera, the most isolated of Australia's detention camps for illegal immigrants, has frequently been the scene of hunger strikes, escapes, riots and attempted suicides in the last two years.

Police are now scaling back their search

Some of the captured detainees are due to appear in court on Monday in connection with their escape - they face a maximum penalty of five years in jail.

Four people have been arrested for allegedly assisting the immigrants to escape.

Three of them have been charged and were bailed to appear at Port Augusta court on 14 August.

If convicted they could face up to 10 years in jail.

The BBC's Sydney correspondent, Dominic Hughes, says an inquiry has been launched into how a group of protesters from outside the camp were able to cut a hole in the perimeter fence and enable the detainees to escape.

Our correspondent says that far from being an organised break-out, it seems to have been a spontaneous action.

And, even more embarrassing for the Immigration Department, there are reports that the private security firm contracted to run the centre only had three staff on duty at the time of the incident.