Forty nine policemen were injured when protesters clashed with security forces over the reopening of a rubbish dump on the Tunisian island of Djerba.
Interior Minister spokesman Khaled Tarrouch said the demonstrators threw stones and firebombs at police and attacked a police station.
They were dispersed with tear gas and two were injured.
The clashes erupted when police tried to clear demonstrators blocking the entrance to the reopened rubbish dump.
The Mediterranean island of Djerba is Tunisia's top tourist destination.
Demonstrations over unemployment and a poor economy have flared around the country over the past week, especially in the impoverished interior.