DUBAI, United Arab Emirates — An appeals court in Bahrain on Thursday upheld the dissolution of the country’s main Shiite opposition group, al-Wefaq, in the latest government clampdown on its critics.

Rights group Amnesty International said authorities in Bahrain have not provided any credible evidence that al-Wefaq “is anything but a peaceful opposition movement” asking for reform.

Bahrain’s Sunni monarchy rules over the tiny island-nation’s majority Shiite population. Mass street protests erupted in 2011 demanding political reforms and greater rights for Shiites. Occasional violent unrest continues to roil the kingdom.

In July, the High Civil Court found al-Wefaq guilty of supporting violence. The ruling called for al-Wefaq to be dissolved and for its assets to be liquidated. The group’s activities were suspended in June and the group’s Secretary-General Ali Salman is imprisoned.

Amnesty International said the July ruling was based on accusations that al-Wefaq supported violence in a series of Twitter posts in 2015, criticized the government and encouraged mass marches.

U.S. Secretary of State John Kerry has previously condemned the decision to dissolve the group, saying the government’s efforts to suppress nonviolent opposition undermine Bahrain’s cohesion and security. The Arab nation hosts the U.S. Navy’s 5th Fleet in the Persian Gulf.

Defense lawyers for al-Wefaq have 45 days to appeal Thursday’s decision to the country’s highest court.

Also on Thursday, three people were sentenced to life imprisonment on charges of attacking police with an explosive. Two of the suspects were tried in absentia, according to the Bahraini news website al-Wasat.

On Wednesday, three Shiite clerics were sentenced to a year in prison each for taking part in an illegal gathering as part of a sit-in to support the country’s top Shiite cleric, Sheikh Isa Qassim, who was stripped of his nationality in June on allegations he encouraged sectarianism and violence.