Bahraini Shiite opposition chief Sheikh Ali Salman rejected charges that he tried to overthrow the country's Sunni regime, as his trial opened Wednesday, a judicial source said.
Hours later, hundreds of supporters gathered outside Salman's home in a Manama suburb and clashed with riot police, who used tear gas to disperse them, witnesses said.
The judge decided to keep Salman behind bars and set the next hearing for February 25, his influential Al-Wefaq bloc said.
Salman, 49, was arrested December 28, sparking near-daily protests across the Shiite-majority but Sunni-ruled kingdom.
The Al-Wefaq head has been accused of "promoting the overthrow and change of the political regime by force" and of inciting disobedience and hatred in public statements.
He was present at Wednesday's hearing before the Higher Criminal Court, which was held under tight security and attended by representatives of several Western embassies.
Salman's defence team called for his release on bail as the opposition chief pleaded not guilty, judicial sources said.
Lawyer Jalila al-Sayed, a defence counsel, denounced what she called irregularities, saying authorities had manipulated Salman's speeches to build their case by removing peaceful comments.
"The conditions are not there for a fair trial," she told a press conference after the hearing.
Salman's arrest has also sparked condemnation from the United States, Iran and international human rights groups.
In a joint statement Wednesday, 109 parliamentarians from 43 countries called for Salman's "immediate release".
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- Like Mandela -
Salman himself, in a letter from prison published on Al-Wefaq's website, likened himself to Nelson Mandela, who spent 27 years in South African prisons during his fight against apartheid.
"I am in prison for the same reasons that led to the imprisonment of Nelson Mandela -- (the call for) equality, freedom and democracy," he said.
"Do not feel sad for my imprisonment. I am ready to spend my whole life as a prisoner for you and for your children's happiness."
Salman said he had been questioned over his calls for an end to "discrimination" against Shiites and for "a democratic regime" in Bahrain.
He urged the international community to "support the Bahraini people in democratically choosing their government... and protect their peaceful gatherings from (state) brutality."
Al-Wefaq said that Salman's "continued detention will only deepen the gap between the regime and the people".
Tiny but strategic Bahrain, which is home to the US Navy's Fifth Fleet, has been rocked by unrest since a 2011 Shiite-led uprising demanding a constitutional monarchy and more representative government.
At least 89 people have been killed in clashes with security forces since 2011, while hundreds have been arrested and put on trial, rights groups say.