The UN in Sri Lanka says dozens of civilians have been killed or injured in fighting between troops and rebels in the north-east in the past few days.
Senior UN spokesman Gordon Weiss told the BBC shells exploded very close to civilian areas in Mullaitivu district.
Mr Weiss said: “The shells landed on the A35 road inside the no-fire zone declared by the army. Some shells landed close to a local UN office.
“Many civilians have been killed or injured. Our staff members witnessed the death of civilians. But we cannot determine where the fire came from.”