Turkey has transferred two British journalists and their Iraqi translator who were arrested this week on terror charges to a new jail in the southern city of Adana, legal sources said Wednesday.

The three, reporting for US-based media outlet Vice News, were detained on Monday and remanded in custody in the mainly Kurdish southeastern city of Diyarbakir in a case that has caused international concern.

They have been charged with "engaging in terror activity" on behalf of the Islamic State extremist group.

Vice News has condemned the charges as "baseless" and "alarmingly false".

The three have now been transferred to a jail in Adana, the head of the Diyarbakir bar association Tahir Elci and legal sources told AFP.

Elci said the reason given for the move was a lack of available English-speaking translators in Diyarbakir.

"This is another example of the mistreatment against the detainees," Elci said.

Legal sources said that even though they were being held in Adana, the investigation would continue to be based in Diyarbakir -- 500 kilometres (300 miles) northeast.

Their detention has drawn criticism from across the world and amplified concerns about declining press freedoms in Turkey.

Vice News, which produces in-depth Internet video reports for the Internet, has named the British journalists as Jake Hanrahan and Philip Pendlebury.

The team had been visiting the region as the government wages a relentless campaign against Kurdistan Workers' Party (PKK) militants, with several local Kurdish officials arrested and accused of supporting declarations of self rule.

A Turkish official on Tuesday denied Ankara played a role in the arrest of the Vice team and said the government is "not pleased" they are being held.