Officials believe the debris is from a Trigana Air Service flight that apparently crashed Sunday with 54 people on board.
Two search planes spotted small pieces of debris Monday in a remote mountainous area of Papua province in eastern Indonesia, said Bambang Soelistyo, the head of Indonesia's search and rescue agency.
Officials deployed two ground teams to the site, which is at an altitude of 2,600 meters (8,500 feet), but suspended efforts to get there because of thick fog.
The teams are in the mountains waiting for better conditions and may have to spend the night there, said Tatang, a senior Papua police official who goes by one name.
Search officials are borrowing a helicopter from Freeport-McMoRan, a mining company, that can use hoists and long lines to lower members of the emergency response team to the scene. But officials said the bad weather also prevented the chopper from flying to the site Monday.
Report of crash from villagers
The plane lost contact with air traffic control on Sunday. There was no indication that a distress call was made from the plane, Indonesian Transportation Ministry spokesman J.A. Barata told CNN Indonesia.
There are many possible reasons for the apparent lack of a distress call, CNN aviation analyst Mary Schiavo said. It could indicate that crew members were too busy dealing with whatever situation arose to send one, or that they didn't realize they were in trouble, she said.
Villagers reported seeing a plane crash into a mountain, according to Indonesian aviation authorities. The site is about 14 kilometers (9 miles) from the airport where the plane was supposed to land.
The plane was carrying 44 adult passengers, five children and five crew members when it went missing just over half an hour into a short domestic flight between Jayapura, the provincial capital of Papua, and Oksibil, an inland town near the border with Papua New Guinea.
All those on board were Indonesian, authorities said.
Few roads, unpredictable weather
The search teams face tough challenges in the dense jungles of Papua's sparsely populated highlands.
Weather patterns are unpredictable in the region, with a tropical climate, tall mountains and moisture coming in from the sea.
Papua has few roads connecting cities, towns and remote tribal villages. To get where they want to go, people either have to take a plane or a boat -- or walk, which can sometimes take months.
"This is a place where some people still hunt their food with bows and arrows while others buy it in supermarkets," the travel guide Lonely Planet says in its description of the province.
A big part of Trigana Air's business is ferrying people and cargo between different parts of Papua.
Before Sunday's crash, the airline had been involved in 19 serious safety incidents since 1992, according to Flightglobal, a website that tracks the global aviation industry.
Eight of the incidents resulted in the loss of the aircraft, and the 11 others involved major damage, Flightglobal said.
Airline on EU blacklist
Trigana is one of a large number of airlines banned from operating in European airspace "because they are found to be unsafe and/or they are not sufficiently overseen by their authorities," according to the European Commission.
It has been on the list since 2007.
The loss of the ATR 42-300 turboprop aircraft is Indonesia's third air disaster in less than eight months.
In December, AirAsia Flight QZ8501 went down in the Java Sea while headed from Surabaya, Indonesia, to Singapore. All 162 people on board were killed.
And in June, an Indonesian military transport plane crashed soon after taking off from the city of Medan, killing at least 135 people.