Bahrain Mirror - AFP: Amnesty International and the European Parliament on Thursday urged Bahrain to release a prominent human rights defender and denounced repression against freedom of expression in the tiny Gulf kingdom.

The London-based rights watchdog called on Manama to drop charges against Nabeel Rajab, who is being tried for "Twitter posts criticising the war in Yemen and allegations of torture in Bahrain's main prison".

It slammed what it called a "farcical trial", in which the head of the Bahrain Centre for Human Rights faces up to 13 years in jail over the tweets.

The Shiite activist has repeatedly been detained for organising protests and publishing tweets deemed insulting to the kingdom's Sunni authorities.

The 51-year-old was re-arrested last month as part of an intensifying crackdown on government critics that has drawn international condemnation.

"They should drop these absurd charges, release Nabeel Rajab and other prisoners of conscience," said Philip Luther, director of the Middle East and North Africa programme at Amnesty.

"The government must halt this brazen crackdown on freedom of expression and accept that everyone in Bahrain has the right to peacefully voice their opinions, including through social media," he said.

The European Parliament slammed "the ongoing campaign of repression against human rights defenders, the political opposition and civil society, as well as the restriction of fundamental democratic rights in Bahrain".

It called for "the immediate and unconditional release of the prominent human rights defender Nabeel Rajab... and other human rights activists" and also for "all charges against them be dropped".

According to his lawyer, Rajab is to appear in court next week over tweets allegedly made in March 2015 about unrest at the kingdom's Jaw prison and the conflict in Yemen, where a coalition led by neighbouring Saudi Arabia launched a military intervention that month.

Home to the US Navy's Fifth Fleet, Bahrain has been rocked by unrest since security forces crushed Shiite-led protests in 2011 demanding a constitutional monarchy and an elected prime minister.