Forces loyal to Libyan leader Muammar Gaddafi have fought a gun battle with Tunisian troops as Libya's conflict spilled over its borders.
Pro-Gaddafi forces shelled the town of Dehiba, damaging buildings and wounding at least one resident, and a squad drove into the town in a truck chasing anti-Gaddafi rebels.
A Tunisian government official told Al Jazeera television that casualties had been inflicted, including a young girl.
Tunisia summoned Libya's ambassador to protest against the incursions.
For the last few days Libyan troops have been harrying rebels from the Western Mountains region. On Thursday, they overran the rebel-held Dehiba border post. Insurgents fled into Tunisia and fighting spilled onto Tunisian soil.
Gaddafi forces accused of mining harbour
NATO accused Colonel Gaddafi's forces of mining the harbour of the rebels' besieged western outpost of Misrata, to block aid ships.
It said sea mines had been laid about 3km from Misrata harbour, used to ferry in humanitarian aid and evacuate wounded to the eastern rebel capital of Benghazi. Three had been found and were being disarmed.
Libyan state television said the port, providing a lifeline to the eastern rebel heartland, had been rendered "non-functional" and any attempt to enter the port "will be attacked".
Colonel Gaddafi's son Saif al-Islam, long seen as a successor to his father, told state television there would be no surrender "if the bombings last for 40 days or even 40 years.