Libyan troops fired rockets from positions controlled by Muammar Gadafy over the border into Tunisia today, witnesses said.
The explosions caused no damage or injuries, but the assault is likely to raise already high tensions between the two countries.
The last time Libyan forces fired rockets into Tunisia, on May 17th, the Tunisian government threatened to report Libya to the UN Security Council for committing "enemy actions".
"At least five rockets fell on Tunisian soil today in the Mrabeh. It was a heavy bombardment from Gadafy's side of the mountains," said one resident.
Anti-Gadafy rebels control the border with Tunisia along Libya's Western Mountains region.
Elsewhere, rebels trying to advance from the Libyan port city of Misrata towards the capital were stopped today when Nato warplanes showered them with leaflets warning of air strikes by combat helicopters.
Rebels said the leaflets, seen by Reuters and plainly meant for forces loyal to Col Gadafy, fell directly on positions the rebels had seized in fighting over the past several days in a painstaking advance towards the town of Zlitan, 160km east of Tripoli.
Some pulled back, fearing Nato planes flying at 15,000 feet might have mistaken them for the enemy.
Any fighting over Zlitan would bring the rebellion closer to the capital Tripoli, the Libyan leader's stronghold which lies 200km west of Misrata.
Rebels from Misrata had said tribal sensitivities prevent them from attacking Zlitan, and they are instead waiting for local inhabitants to rise up.
Late yesterday, six rockets hit generators at the refinery near Misrata port leaving them heavily damaged. An engineer on site said it was unclear how long it would take to repair.
The head of the British Royal Navy sparked questions about how Britain will cope with a prolonged conflict in Libya after warning cuts would be needed elsewhere if it lasted beyond six months.
In comments that immediately reopened controversy over the British government's deep defence cuts, First Sea Lord Admiral Sir Mark Stanhope also said elements of the operation would have been cheaper and "much more reactive" if the aircraft carrier HMS Ark Royal had not been scrapped.
But he insisted he was not calling for the decision to axe the vessel and its Harrier jump jets - part of wide-ranging cuts to the armed forces announced last year - to be reopened.
Responding, British defence secretary Liam Fox said the United Kingdom’s leading role in the intervention had shown it remained a “leading military power” and had the resources necessary to take part.
Reuters