The clashes between the Tunisian security forces and unidentified groups of armed men, which began late Friday and lasted through early Saturday, resulted in casualties, Tunisia's official TAP news agency said.
It was not immediately clear how many victims there were, nor whether they were injured or killed.
A local resident alerted security officials to the presence of pickups carrying armed men.
Tunisian territory has come under fire from neighboring Libya, where rebels are struggling to oust leader Moammar Gadhafi. Thousands of Libyan civilians have streamed into Tunisia over the past months, seeking refuge from the fighting.