Human Rights Watch (HRW) accused the government of firing into an area designated as a "no-fire zone" packed with civilians and the remnants of the separatist Liberation Tigers of Tamil Eelam (LTTE).
"Sri Lanka’s so-called ˜no-fire zone’ is now one of the most dangerous places in the world," said Brad Adams, HRW's Asia director.
"The Sri Lankan government should stop firing heavy artillery into the 'no-fire zone,' and "causing skyrocketing casualties," said Adams.
International concern has been mounting for some 100,000 civilians that the United Nations says have been trapped by fighting.
Sri Lankan troops were setting up "rescue points" just outside the government-designated no-fire zone to allow civilians to make a dash for safety, the defence ministry sa