A trial of five Turkish reporters accused of insulting the country's judiciary has been adjourned in Istanbul amid scuffles in court.
Journalist Hasan Cemal said he had simply used his right to free speech
At the opening session, nationalists who brought the charges yelled abuse at the judge and fought with riot police.
The charges relate to comments the five made on the killing of Armenians in the Ottoman Empire during World War I.
A similar case against prominent writer Orhan Pamuk which sparked international uproar was dropped in January.
The cases, seen as a test of Turkey's attitude to free speech, have been criticised by the European Union - a body Ankara wants to join.
Before a large crowd in court, the nationalist lawyers yelled their demands to be part of the official prosecution, says the BBC's Sarah Rainsford, who was at the journalists' trial.
Demonstrators chanted nationalist slogans outside the court
Then they turned on foreign observers, shouting that they had occupied a Turkish court, our correspondent says.
When the judge ordered armed riot police to evict the ringleader, his friends fought back in a furious scuffle that lasted several minutes.
The nationalists filed a petition demanding the trial judge be replaced.
The defence team, meanwhile, submitted their reasons why the case should never have been brought in the first place.
The judge then decided to adjourn proceedings until 11 April to consider their arguments.
The journalists, who write for Turkey's leading newspapers, wrote articles criticising a court decision to ban a conference on the killing of Armenians between 1915 and 1917.
The men are being tried under article 301 of Turkey's penal code, which makes it illegal to insult any organ of state. They face six months to 10 years in prison if convicted.
One of the journalists, Hasan Cemal, on Tuesday urged the government to observe EU standards on human rights.
"I did nothing but enjoy my right to freedom of expression by saying that the... conference was necessary and that the court was hampering the proper functioning of democracy," he told the AFP news agency.
The other four defendants are Murat Belge, Ismet Berkan, Haluk Sahin and Erol Katircioglu.
Last year, Orhan Pamuk was tried under article 301 for comments he made on the killing of Armenians, but charges against him were dropped in January.
The mass killings have been a taboo subject in Turkey.
Ankara says the deaths of Armenians in conflicts during the collapse of the Ottoman Empire were not part of a genocidal campaign.