The bund, a mined earth mound surrounded by a moat, is one of a series dug by the rebels to slow the advance of army troops into their final stronghold on the island’s north-east coast.
Britain, the United States, the United Nations and the European Union believe the army is continuing to shell Liberation Tigers of Tamil Eelam (LTTE) positions in the so-called ‘no fire zone’ where an estimated 50,000 civilians are trapped.
A cross-party delegation of British MPs, led by former defence minister Des Browne have begun a two-day trip to the island and will visit refugees who have escaped from fighting in the no-fire zone.
It will be Mr Browne’s first visit since Colombo rejected his appointment as Britain’s special envoy to Sri Lanka to lobby for a humanitarian ceasefire and progress towards a political settlement.
But in heavy fighting on Monday, Colombo demonstrated its determination to resist international pressure and continue its ferocious advance into the tiny ‘no-fire zone’.
Its defence ministry said its 58 and 53 Divisions had cleared the main barrier to retaking the remaining three mile strip after they "stormed" the bund on the A35 road between Paranthan and Mullaittivu.
Their statement appeared to contradict earlier indications that future operations would be low key and led by special forces using small arms to avoid civilian casualties.
(For updates you can share with your friends, follow TNN on Facebook and Twitter )