Forces loyal to Libyan leader Muammar Gadafy bombarded rebel positions at a border crossing with Tunisia which has changed hands twice since yesterday, residents of the nearby Tunisian town of Dehiba said.
"Very heavy bombardments by Gadafy's forces have started. They are trying to take the post back again," said one Tunisian, Ramzi.
Col Gadafy's son Saif al-Islam said today that Libya would never surrender to the Nato bombings.
"If the bombings last for 40 days or even 40 years, there will be no surrender," Saif al-Islam told Libyan television. "[Libya's] green flag will remain high."
Pro-Gadafy forces fired shells into Dehiba, damaging buildings and injuring at least one resident, and a group of them drove into the town in a truck, local people and a Reuters photographer in the town said.
The Libyan government troops were pursuing rebels from the restive Western Mountains region of Libya who fled into Tunisia in the past few days after Col Gadafy's forces overran the border post the rebels had earlier seized.
Late yesterday, Tunisia's government issued a statement condemning incursions by Libyan forces after shells fired by Gadafy loyalists fell into the desert near the border.
"Given the gravity of what has happened . . . the Tunisian authorities have informed the Libyans of their extreme indignation and demand measures to put an immediate stop to these violations," a statement from the foreign ministry said.
Today's clashes marked the first time that Libyan government ground forces had crossed the border and entered a Tunisian town.
Residents said that a crowd of local people gathered in Dehiba this morning to try to prevent pro-Gadafy forces from entering the town. They said the Tunisian military fired in the air to disperse them, and urged the demonstrators to seek shelter from the shelling inside their homes.
Tunisia toppled its own veteran leader, Zine al-Abidine Ben Ali, in a revolution earlier this year, and many people there are sympathetic to the rebels fighting Col Gadafy's forces.
Elsewhere, Nato air strikes today hit Gadafy forces that had been attacking the rebel held town of Zintan, a rebel spokesman told Reuters.
Five missiles landed in the area," the spokesman said by telephone from the town. "Gadafy's forces did not bombard Zintan today after the air strikes," he said.
Reuters