Kathmandu - A commission formed by the Nepalese government Saturday began its investigations into the plane crash in north-eastern part of the country that killed 18 people, mostly tourists, officials said.

The five-member committee, which includes the deputy attorney general and pilots, flew to Lukla, the site of the crash, about 150 kilometres north-east of the Nepalese capital.

The Twin Otter aircraft crashed while landing at the airport on Wednesday killing 12 Germans, four Nepalese and two Australians.

The team will interview airport officials, police, witnesses and local residents about the circumstances surrounding the crash, the Nepalese home ministry said.

Earlier in the week Nepalese officials said they suspected bad weather at the airport as the main cause of the crash.

"The approach to the airport was covered by thick fog that rose up the mountain, obscuring the approach seconds before touch town," said Mohan Adhikari, the director general of the Civil Aviation Authority of Nepal. "We are looking at weather as one of the main reasons for the crash."

The commission has been given two months to submit its report.

In Kathmandu, German experts began efforts to identify the bodies, following the arrival of more experts, including dental experts, on Friday.

However, Nepalese officials said it was becoming difficult to identify the victims because of lack of equipment and facilities in Nepal.

"The experts will collect DNA samples and check dental records to identify the victims," said Dr Tulsi Kadel who heads the autopsy team at Tribhuvan University Teaching Hospital in Kathmandu where the bodies are kept.

"There are no facilities to carry out DNA testing in Nepal so it has to be sent outside the country and that could take some time,' Kadel said.

The Lukla airport is considered one of the most dangerous in the world with its runway sloping downwards and one side ending in a steep cliff.

It is an important airport for thousands of tourists on their way for trekking in the Mount Everest region. (dpa)