Aircraft from Singapore arrived in Indonesia on Wednesday (January 3) to join the country's intensive search for a plane that had 102 people on board when it disappeared in bad weather four days ago. Singapore has supplied two Fokker -50 surveillance aircraft for the search and the United States was also known to be offering unspecified aid, officials announced on Wednesday. "We will be cooperating with the Indonesian air force tomorrow. We will have talks and discussions on how to utilise the Singaporean planes on finding the missing plane," said Keith Rodriguez, a member of the Singapore Air Force, upon arrival at Hasanuddin Air Base. Indonesian air officials vowed to work closely with their foreign helpers in finding the missing Adam Air plane. "The Singaporean military is here to help our search and rescue team find the missing Adam Air plane," said Eddy Suyanto, commander of Hasanuddin Air Base. A total of two helicopters and six fixed-wing aircraft were also involved the search, said Suyanto. Military and civilian rescuers have been hunting for the plane over the dense jungle and rugged mountains of western Sulawesi while navy vessels combed the Makassar Strait between Sulawesi and Borneo. But the search efforts have been hampered by heavy rains and strong winds, as well as the rough terrain which has made communication and transport difficult. Senior government officials apologised late on Tuesday (January 2) for erroneously saying the 17-year-old Boeing 737-400, operated by budget carrier Adam Air, had been spotted on Sulawesi and 12 passengers had survived. The missing plane was carrying 96 passengers and six crew. A copy of its manifest showed three passengers as non-Indonesians. The U.S. embassy in Jakarta said they were Americans. The search effort is being coordinated from Makassar, Sulawesi's largest city, 1,400 km (875 miles) east of Jakarta. South Sulawesi governor Amin Syam said on Wednesday that many rescuers were worn out after following Tuesday's false alert. Relatives of those who boarded the plane were also exhausted and emotionally torn as they waited at Adam Air agencies for search updates. "I am still hoping that she'll come back. Thank God if she has survived, but if not I will have to accept this fate," said Rosma Dewi, the mother of one of plane's cabin crew members. The confusion over the missing plane highlighted the logistical difficulties of dealing with disasters, from quakes and volcanoes to floods and forest fires, in an archipelago of 17,000 islands that stretches about as wide as the United States. President Susilo Bambang Yudhoyono has ordered a full investigation into the condition of all commercial planes in Indonesia and what went wrong in the Adam Air case, as well as an evaluation of the nation's transportation system.