Sheikh Ali Salman
Sheikh Ali Salman is a 'prisoner of conscience', according to AmnestyReuters

Bahrain opposition leader Sheikh Ali Salman has been sentenced to four years in jail for inciting violence against the ruling system, according to his al-Wefaq party.

The party wrote on Twitter:

Salman, who is considered a "prisoner of conscience" by Amnesty International, was arrested on 28 December, two days after calling for serious political reforms in the Gulf country.

He was charged for "incitement to promote the change of the political system by force, threats and other illegal means" and other related charges.

His trial has been marred by a series of violations, including a reported ban on Salman and his lawyers from presenting oral arguments. Lawyers for the Shi'ite opposition leader also complained that the evidence used against him contained abstracts from his speeches taken out of context.

"The detention and trial of Sheikh Ali Salman is a blatant violation of his right to freedom of expression and demonstrates the Bahraini authorities' continued attempt to suppress political opposition and silence critical voice," Amnesty said, calling for his release.

After the crackdown on the pro-democracy uprising in 2011, led by Saudi forces, Bahrain has plunged deeper into sectarian conflict between the wealthy ruling Sunni-al-Khalifa minority and the Shia majority.

King Sheikh Hamad bin Isa Al-Khalifa has pledged to implement recommendations by an independent commission of inquiry but reforms are progressing slowly and reconciliation talks have stalled. Violence between riot police and protesters is a weekly occurrence.

Decrees approved by Hamad include up to seven years in jail for criticising him. All protests, sit-ins and gatherings in Manama are banned indefinitely.