At least two Sri Lankan war refugees were wounded when soldiers fired as they tried to flee a state-run camp, the military said on Sunday, Reuters reported.
"On Saturday evening a group of people were trying to escape and a man tried to lob a grenade. Our people (soldiers) fired toward that area for self defense and to prevent escape," said Military Spokesman Brigadier Udaya Nanayakkara.
The two wounded Tamils were admitted to hospital and 19 people were arrested, he added.
The United Nations, is pushing the Indian Ocean island to let refugees go home following its victory in May over separatist Tamil Tiger fighters, after 25 years of war.
Sri Lanka says it must clear thousands of landmines and weed out remaining rebels hiding among the civilian population before it can fulfill its pledge to resettle 80 percent of the 280,000 Tamil people in camps.
Rights groups have charged that the people in the camps are treated poorly and are being kept there longer than necessary.
The government has said it has released 15,000 refugees since the end of the war in mid-May. United Nations data says nearly 12,000 have been sent home, about half of them elderly refugees released either to rest homes or the care of relatives.