The trials of 30 Tibetans, which led to their conviction for alleged role in the recent Tibet [Images] unrest, were not open and public as claimed by China, a leading rights watchdog alleged on Wednesday.

While the reports from the official Xinhua news agency termed the proceedings as an open court session, the actual trials had been conducted covertly on undisclosed dates earlier in April, the Human Rights Watch said.

"Guilty or innocent, these Tibetans are entitled to a fair trial," said Sophie Richardson, Asia advocacy director at the HRW.

"Instead, they were tried on secret evidence behind closed doors and without the benefit of a meaningful defence by lawyers they'd chosen," she said.

The Intermediate People's Court in Lhasa, capital of the Tibet Autonomous Region, conducted a 'sentencing rally on Tuesday, during which Tibetans, including six monks, were handed over sentences, ranging from three years to life imprisonment.

The HRW said that severe flaws in the regional authorities' handling of the Tibetan protests precluded fair trials of people suspected of having participated in the disturbances.

These flaws included a consistent failure to establish a distinction between peaceful and violent protesters, remarks by the Public Prosecution at the time of suspects' arrests that assumed their guilt rather than innocence and secret trial proceedings.

In addition, these 30 Tibetans may have been denied their right to their own counsel, the rights watchdog said.

Besides, all the lawyers who had publicly offered to defend Tibetans were forced to withdraw their assistance after judicial authorities in Beijing [Images] threatened to discipline them and suspend their profession.