A small passenger plane on a domestic flight in Thailand crashed Thursday afternoon shortly after taking off from the main airport in the capital, Bangkok, the country’s civil aviation authority announced. It appeared that all nine people aboard had been killed.

Rescuers found no survivors at the crash site in a mangrove swamp in Chachoengsao province about 40 kilometers (25 miles) from the airport, reported Thai media, which said seven passengers and two pilots had been listed as being on board.

After about an hour of searching, rescuers found badly shattered body parts in the difficult, swampy terrain, said a spokesperson for the provincial government.

The names of those on board were not immediately available. However, the spokesperson said they included five Chinese tourists from Hong Kong, two Thai female crew and the Thai pilot and co-pilot.

The cause of the crash is not yet known.

The Civil Aviation Authority of Thailand said the turboprop plane, a Cessna Caravan C208B operated by the Thai Flying Service Company, had departed Bangkok’s Suvarnabhumi Airport at 2:46 p.m. (0746 GMT). Air traffic control lost radio and radar contact with the aircraft 11 minutes later, when it was an estimated 35 kilometers (22 miles) southeast of the airport.

It had been headed to Trat, a coastal province about 275 kilometers (171 miles) southeast of the Thai capital.

Video from the scene showed highly fragmented pieces of the plane in water in the middle of a wooded area. A rescuer could be seen in muddy water up to his chest.

The Chachoengsao provincial spokesperson said further searches were going slowly because it was already dark and the rising tide had flooded the crash site with more water.