DAR ES SALAAM (Reuters) - Muslim protesters clashed with police in Tanzania's commercial capital on Friday during a protest over the arrest of a hardline Islamic cleric, witnesses said.
Police fired tear gas and at least 30 people were arrested. Similar demonstrations have erupted sporadically over the last few weeks, raising religious tensions in the relatively stable and secular east African country.
Sheikh Ponda Issa Ponda was arrested last month and charged with illegally trespassing on private property and theft. He is in police custody after failing to make bail.
"Immediately after Friday prayers, worshippers came out of the Tandamti mosque and confronted policemen stationed outside the mosque," said resident Omary Haji, who witnessed the clashes in Dar es Salaam.
"The worshippers started throwing stones at police, who responded by firing tear gas at protesters."
A police source said at least 30 people had been arrested. A Reuters witness said Kariakoo, a market place near the city centre, was deserted and many shops and offices had closed in anticipation of unrest.
"We were informed by police there could be riots and they advised us to close our offices before noon," said Michael Ndosi, who works at a travel agency in the city centre.
Ponda is the secretary general of the Council of Islamic Organisations, a group that vies for influence with the government-backed National Muslim Council of Tanzania.
Off the shores of Dar es Salaam, an Islamist separatist group in the semi-autonomous, mostly Muslim archipelago of Zanzibar has spearheaded protests after the group's spiritual leader briefly disappeared in unknown circumstances.
The unrest in Zanzibar mirrored similar discontent further up the Swahili coast where a Kenyan separatist group has called for the secession of Coast province that is home to large Muslim communities.
The protests are a headache for the secular governments in Nairobi and Dodoma. The poor, Muslim coastal areas have proved a fertile recruitment ground for Somalia's al Shabaab militants.
(Reporting by Fumbuka Ng'wanakilala; Writing by Yara Bayoumy; Editing by Richard Lough and Robert Woodward)