Police say they have arrested 43 suspected members of an Islamist group seeking greater independence for the country's Zanzibar archipelago.

Police official Mussa Ali Mussa said Sunday the suspects of the Association for Islamic Mobilization and Propaganda were arrested since a protest rally on Friday that security forces dispersed with tear gas and water cannons.

The group has been gaining popularity in Muslim-dominated Zanzibar, which is a popular Indian Ocean tourist destination off the East African nation's coast.

Mussa said the UAMSHO group staged Friday's illegal protest at a mosque using the pretext they were praying for the victims of a ferry accident off the island that cost almost 150 lives this week.

UAMSHO leader Farid Hadi says the group was peacefully mourning the victims but was attacked by police.