An exhaustive search and rescue effort for three travellers reported missing en route to Lutsel K'e from Dettah remains open as attempt to identify debris spotted in an "area of interest," between the two communities.

Samuel Boucher, 65, Cammy Boucher, 23, and an unknown male were reported overdue to police after departing Dettah around 10:30 p.m. Monday.

The missing group, travelling aboard a 1990SA国际影视传媒檚 era black Bombardier Scandic two-seater that towed two toboggans, prompted a far-reaching, four-day aerial search that concentrated on a "triangular" area stretching between Yellowknife, Fort Resolution and Lutsel K'e, Sgt. Christina Wilkins of the Yellowknife told reporters outside the detachment during a press briefing Friday night.

Air searches were conducted by two airplanes and two helicopters each day from Tuesday evening to today.

On Thursday, during day-four of what she called an "extensive" aerial search, an aircraft spotted debris in an open body of water "closer to Lutsel K'e" than Dettah, Wilkins confirmed to reporters.

"Searchers were able to land on a nearby landmass, but were unable to land on the thin ice near the open body of water," said Wilkins.

She wouldn't specify exactly where the debris was found - or what is was.

Investigators are now reviewing the debris to determine if any of the items may belong to the missing individuals, said Wilkins.

So far, the entire search has been restricted to the skies.

SA国际影视传媒淭reacherousSA国际影视传媒� and SA国际影视传媒渄eterioratingSA国际影视传媒� ice conditions on Great Slave Lake and its shores have made ground searches too dangerous for , who have been forced to limit all their efforts to air searches.

"Our conditions are changing on a daily basis," said Wilkins Friday. "We have a lot of unstable terrain; unsafe areas on the ice."

The initial search, spanning a 7,200 square kilometre area, has expanded over four days to effectively encompass all of Great Slave Lake.  Airplanes and helicopters have now travelled approximately 20,000 kilometres as part of the search.

The active status of the operation, she said, "all depends on the information we get back over the course of the next few hours and days."

"It changes from hour to hour. At this point (the search effort) remains ongoing," she told reporters.

While the third traveller, a male, remains unidentified by police, Wilkins said "have a fairly good idea," who he is.

But, she said, protocol, including the need to contact family, must be followed before any confirmations can be made.

Wilkins said have been in close contact with the families of the two known individuals, providing them with updates as the search continues.

are urging residents not to go out looking for the missing travellers themselves.

SA国际影视传媒淲e understand the desire to bring these travellers home, but due to the deteriorating ice conditions, we stress that no one should venture out on the iceSA国际影视传媒� stated Yellowknife staff Sgt. Yannick Hamel in a May 16 news release.

In a news release issued after Friday's briefing, Hamel wrote, "Our hearts are with the families as we draw to the close of day 4. We will continue to support them in this difficult time."

Police ask anyone who sees something or has information that could assist the ongoing search and investigation to contact .

Updates to follow.