Philippine authorities on Monday launched a search mission on the Philippine volcano after spotting

Philippine authorities on Monday launched a search mission atop a restive volcano after spotting the suspected wreckage of a missing plane carrying two Australians along with a Filipino pilot and crew member.

The six-seater Cessna 340 aircraft was bound for the capital Manila when it lost contact with air traffic control on Saturday after it left Bicol International Airport in Albay province, said the Civil Aviation Authority of the Philippines (CAAP).

The two Australians – Simon Chipperfield and Karthi Santhanam – were technical consultants working for Energy Development Corp., a Manila-based geothermal firm, the company confirmed in a statement.

“It’s now the fourth day since they’ve gone missing, and considering the terrain and harsh weather, it’s a difficult and challenging situation … we continue to hope and pray that we will locate them,” Allan Barcena, the company’s assistant vice president and spokesman, told CNN on Tuesday.

In the statement, the company said its emergency response team had located wreckage at an altitude of about 6,000 feet (1,823 meters) near Mount Mayon, which last erupted in 2018, on Sunday.

“We only have aerial photos – the drone shots – but we cannot confirm if that is the said aircraft. Our accident investigators need to see the actual crash site on the ground,” Apolonio said.

“We need to find the plane first before we can determine what caused the crash.”

The wreckage is located near a “permanent danger site” and a determined “no-fly zone” around the volcano, and rescue teams have been given permission by the Philippine Institute of Volcanology and Seismology to begin the high-risk search operations, he said. Heavy rain and risk of landslides have added difficulty to the search.