A pro-Tamil Tiger website on Tuesday accused Sri Lankan government forces of continuing to pound civilians trapped in rebel-held territory despite a pledge to stop using heavy weapons.
Security forces fired multi-barrel rockets and mortars at the narrow strip of coastline still in the hands of the Liberation Tigers of Tamil Eelam (LTTE), Tamilnet said.
"There was heavy mortar fire from many directions," the website said, adding that 139 people were wounded in attacks on Monday evening.
Sri Lanka's military, however, denied it used heavy weapons but confirmed that it was trying to capture more territory and free the civilians its says are being held by the Tigers as human shields.
Colombo on Monday announced it was halting the use of heavy weapons and air strikes to spare civilian lives in the face of growing international pressure.
"We did not shell the area. We have not used heavy weapons against civilian areas even before," said Sri Lankan military spokesman Brigadier Udaya Nanayakkara.
"But ground operations to capture territory and rescue civilians will continue."
Top United Nations humanitarian official John Holmes welcomed Colombo's declaration on Monday but said he was disturbed by reports of continued shelling.
"I hope it (the government declaration) will be genuinely respected this time," Holmes said. "It has not happened in the past."
He said he had heard reports of fresh shelling in the conflict area where some 50,000 civilians are trapped, but had no way of verifying the claims and counter-claims.
"If it is happening, the shelling must stop. It is very disappointing if it is true," he said, wrapping up a three-day visit to Sri Lanka on Monday night.
Holmes failed to secure an agreement from the Sri Lankan government on opening up the conflict area for humanitarian aid and relief workers.