YANGON (Reuters) - Three journalists jailed in Myanmar after contacting ethnic minority rebels questioned on Tuesday (July 18) the role of the military in their detention and trial, as they made an unannounced court appearance.

Soldiers took media professionals Aye Nai, Pyae Phone Aung and Lawi Weng, and three ethnic minority men travelling with them, into custody on June 26.

The journalists were on their way back from reporting on some illegal drugs being burned by the Ta'ang National Liberation Army, a rebel group fighting the army for greater autonomy.

In video filmed after the procedural court hearing on Tuesday, released by Democratic Voice of Burma (DVB), the three are seen giving their first comments to media since their arrest.

Aye Nai said in the video they were held for two days and questioned by members of an army regiment based in the northeastern town of Hsipaw before being handed over to police.

The military then filed charges accusing all six of"unlawful association" under a colonial era law.

"The Ministry of Home Affairs should be handling the case, but the military is handling the case and I think it shouldn't be like that," Aye Nai says.

The military's communications unit, the True News Information Team, could not immediately be reached for comment.

The military ruled Myanmar for decades after seizing power in a 1962 coup but has made way for a civilian government led by democracy champion Aung San Suu Kyi, whose party swept an election in late 2015.

But Nobel laureate Suu Kyi remains constrained by a Constitution that protects the military's role in politics.

The case of the three reporters has raised concern in the media in Myanmar that gains in press freedom since the beginning of the transition from full military rule could be going into reverse.

Journalists have warned that jailing colleagues for doing their jobs would have a chilling effect on freedom of expression.

The DVB, the employer of Aye Nai and Pyae Phone Aung, and the Irrawaddy magazine, where Lawi Weng is a senior reporter, were both set up in exile when the military still held full power and stifled the press.

Both publications set up bureaus in the commercial hub Yangon after the government dropped pre-publication censorship in 2012.

The court in Hsipaw had previously announced that the six men would appear on Friday (July 21), but the case was unexpectedly brought forward, meaning at least one lawyer was absent on Tuesday.

"I planned to go there on Friday, the scheduled date. I was not informed that the court date was moved," the DVB reporters' lawyer, Mr Maung Maung Win, told Reuters.

In the video, the six men are all seen chained together with handcuffs.

"Can you call this democracy? People have been shouting about democracy," says Lawi Weng. "This is a threat from the military."