The deputy prime minister of Thailand's caretaker government urged on Friday for an investigation into a passenger plane crash to be done as soon as possible, as he visited the site of the crash in Chachoengsao Province.

The plane carrying nine people crashed into a mangrove forest in Bang Pakong district in Chachoengsao Province, en route from Suvarnabhumi Airport to Trat Airport. The accident occurred just 10 minutes after it departed at 2:46 pm on Thursday.

All on board, including four Thais and five Chinese tourists, were found dead, according to the Civil Aviation Authority of Thailand. Of the five Chinese victims, there were two teenagers aged 12 and 13. Hong Kong immigration authorities said the victims were not residents of the special administrative region.

Interior Minister Anutin Charnvirakul, also deputy prime minister of the caretaker government, said the cause of the accident should be determined as soon as possible.

"Although 40 percent of plane parts have been found, we need to wait for further analysis to identify the wreckage. Everyone is trying their best to help, including the rescue team and even villages nearby that came to assist. I expressed my appreciation to all of them," Anutin said.

Investigation needed

He also said none of the plane parts being found is complete, which is very sad. He added that the plane's vertical fall was abnormal, which should be investigated by experts.

When asked whether the accident happened because the plane was used for a long time, Anutin said all aircraft follow strict standards and will be in service up to the end of its service life. He also expressed confidence in the pilot's professional skills.

Thai media reported that the nine victims have been identified. However, the black box has yet to be located and is believed to be submerged underwater beneath the wreckage.

Rescue teams, including forensic experts from the Royal Thai Police, are running against time on the crash site, facing challenging terrain and weather conditions.

The aircraft, a Cessna Caravan C208B, was operated by the Thai Flying Service. Flight TFT209 was carrying five passengers, two flight attendants and two pilots, the Civil Aviation Authority of Thailand said.

One witness reported hearing a loud explosion before the plane crashed into the forest, with debris hitting a nearby house, The Nation reported.

After receiving the crash report at 3:30 pm, local rescue teams arrived at the scene and found the wreckage of the small plane scattered and submerged in mud, with a skid mark about 100 meters long.

The plane had plunged nose-first, embedding itself more than 10 meters deep into the muddy ground. The search for missing victims continues.

yangwanli@chinadaily.com.cn