Forces loyal to Libyan leader Moammar Gadhafi clashed with Tunisian soldiers Friday, after crossing the border while pursuing rebel fighters.
Witnesses say Tunisian forces fought back, pushing the pro-Gadhafi soldiers back into Libya.
Libyan forces have been trying to reclaim the border crossing, in the western Wazin region, which was seized by rebels last week.
Tunisian officials say thousands of Libyans have fled to Tunisia during the past few days to escape the fighting.