The trial was later adjourned until Monday to give the prosecution and defence more time to call on witnesses. However, defence lawyers had reportedly claimed they needed at least a month to prepare their case.
The prosecutor-general had requested reporting restrictions because of the publication of "inaccurate and false reports related to the trial".
Earlier, a correspondent of the Yemeni paper al-Ayyam was detained after the newspaper published a full transcript of the first day of the proceedings last Wednesday.
Stephen Jakobi, of the legal rights group Fair Trials Abroad, said that the restrictions were "a clear breach of international law", and that the proceedings were turning into "an empty show trial with no pretensions to justice", because the defence lawyer has no access to prosecution documents or lists of witnesses.
The defendants arrived at the courthouse in an armoured truck accompanied by a convoy of military jeeps. The building was surrounded by more than 200 policemen armed with AK-47s. The suspects were flanked by soldiers as they entered the courtroom, which was packed with members of their families, foreign and local journalists, diplomats and lawyers.
Police have charged the six men with associating with armed groups, forming a plan to commit murder and destruction, and possessing weapons. The prosecution strategy is to show that the defendants in Aden, Abu Hamza in London and the kidnappers of 16 tourists, four of whom were killed, formed a closely coordinated conspiracy. The defendants have denied all charges.
Prosecution witnesses said the Britons were first suspected when they fled a checkpoint in their car. The police said it was later found abandoned after a high-speed chase, but with explosives, mines and a rocket launcher in the boot.
The defendants, who say they have been tortured, shouted from the dock that they had not been examined by an independent medical expert. The court yesterday approved a request by the defence lawyer to allow a British doctor to examine the defendants.
Sirmad Ahmed, one of the accused, said: "We are being stitched up and framed and what is the British Government doing about it?" Malek Nasser Harhara, another defendant, denied that any weapons were in the car and said the account of a high-speed chase was exaggerated.
The government had announced that Mohammed Mustapha Kamil, the son of Abu Hamza al-Masri, the militant Islamic cleric based in London, and two other Britons arrested last week in Yemen would join the defendants in the dock, but they did not appear. A security source said they were still under interrogation.
One of the three Germans kidnapped by Yemeni tribesmen on Tuesday has been freed. The 30-year-old aid worker was taken along with her mother and brother who were visiting her.
t Clare Short, the International Development Secretary, pleaded for people not to make accusations against the Yemeni authorities which would harm the Britons' case or increase tension.
"There have been some very extreme statements about what is going on," she told Radio 4's Today programme. "I do caution those who care about these men and their families not to say crazy things. The situation is very serious; the charges are very serious. We must make sure they have proper representation and that they have a fair trial."