Rescuers scoured the Thai jungle Friday for nine missing people after a turboprop plane crashed southeast of capital Bangkok, though authorities expected no survivors.

The aircraft went down in the jungle of Chacheongsao province on Thursday, and all on board were believed dead, Thai officials said.

Nine people -- including two pilots and seven passengers -- were travelling from Bangkok's Suvarnabhumi airport to Trat province, an area on the Gulf of Thailand known for its beaches, when the plane went down.

"It happened at around 3:10 pm (0810 GMT). We are trying to find those missing, but we believe that they are all dead," Chacheongsao governor Chonlatee Yangtrong told reporters at the scene Thursday.

According to local media, passengers included four Thais and five Chinese including two children aged 12 and 13.

More than 300 military personnel and volunteers have been deployed in the search, and authorities have launched an investigation to identify the cause of the crash.

They have found some body parts, as well as pieces of the aircraft, authorities said.

But heavy rainfall is hampering the search.

"We are not planning to stop until we find them, although there are some waterlogged areas," Chonlatee said.