* Car windows smashed, buses torched
* Arrest strained relations between Islamic orders, state
DAKAR, Oct 22 (Reuters) - Scores of followers of a jailed Senegalese religious leader smashed car windows, set fire to buses, and ransacked shops in the capital Dakar on Monday before riot police scattered them with volleys of teargas.
The riot was the most violent protest yet by followers of Cheikh Bethio Thioune, a senior member of the powerful Mouride brotherhood, since he was arrested in April in a murder case that has strained the relationship between Islamic orders and the country's justice system.
"This is absolutely despicable," said Djibril N'Diaye, an official with Dakar's bus drivers' union, standing next to the charred remains of a city bus. "The authorities should have protected us from this."
Youths carrying sticks and using chunks of concrete overturned market stalls, bashed store fronts and broke the windscreens of more than 100 cars in Dakar's main square, according to a Reuters witness.
The riot follows a demonstration late last week outside the Dakar prison where Bethio is being held, and comes amid reports of much smaller protests elsewhere in the country.
Bethio is the first leader of his stature to be arrested in years in the heavily Muslim West African state, where the line between religion and politics is often blurred.
Two of Bethio's disciples were killed in April at his house after a dispute, and their bodies were hastily buried, according to local media. His lawyer said Bethio faces charges of complicity in the murders.
Bethio backed former president Abdoulaye Wade in his failed re-election campaign earlier this year. Under Wade, critics complained that some people close to the presidency were untouchable by the justice system.
Newly elected President Macky Sall, who took office in April, is under pressure to investigate reports of corruption during Wade's rule and has pledged not to interfere in the justice system. (Writing by Richard Valdmanis; Editing by Michael Roddy)