Tunisia's government says a police officer has died in clashes with young protesters who had overturned his car during one of a series of demonstrations against mass unemployment.

Tensions have risen in the Kasserine region since Sunday when an unemployed youth killed himself by scaling an electricity transmission tower to protest his rejection for a government job. Protests spread overnight into Thursday to several cities, including the capital, Tunis.

Unemployment is around 15 percent in Tunisia, but far higher outside the capital region. Among young people, it's around 30 percent.

Interior Ministry spokesman Walid Louguini said the police officer was "fatally attacked" by the crowd as he tried to leave his car. Unrest elsewhere left about 40 people injured during clashes between police and protesters.