By Erika Solomon and Evrim Ergin

KILIS, Turkey (Reuters) -- Syrian refugees sheltering in containers at a Turkish refugee camp at the border town of Kilis have spoken of their terror after troops loyal to President Bashar Assad shot dead a rebel fighter within yards of their encampment.

Fleeing a year-long crackdown on anyone who opposes the government, the refugees had hoped to find sanctuary just inside the Turkish border. But instead, on the eve of a UN-backed ceasefire, they say the bloodshed they were seeking to escape has come to their doorstep, spreading fear and the occasional stray bullet among thousands of men, women and children.

"The last two nights we've been right next to the fighting," said 26-year old Tarek, who fled the town of Jisr al-shughur nine months ago.

"As soon as people in the camp hear a gunshot now, they dive to the floor. People on the side closest to the border go hide in the homes of those on the farther side of the camp."

The fighting continued to rage on Wednesday evening, he said.

"We couldn't see the fighters because it is dark. But we could hear heavy gunfire and I saw red tracers in the sky."

Stray bullets from clashes between the army and the rebels ripped through the camp on Monday, injuring two refugees and two workers, provoking a furious response from Ankara, which is sheltering around 25,000 Syrians in camps dotted along the border.

"The atmosphere in the camp is really tense," said another refugee, 25-year-old Ibrahim, also from Jisr al-shughur.

"What is frightening is how close the Syrian army is getting to our camps, we can look through the fence and see them out there. Obviously for people fleeing the regime that is the last thing you want to see at night," added the scrawny young man with a long black beard.

Refugees at the Kilis camp said they had shouted "you dogs, you dogs of Bashar" as they watched two Syrian soldiers loyal to Assad run towards an object in the tall grass outside the camp, shoot at it with machine guns, and then pull what looked like a bullet-proof vest from a body.

The body, that of a wounded rebel who had tried to crawl over the border to safety, was still lying there in no man's land, Tarek said, a grim warning of the risks such fighters face.

"They didn't just shoot him dead, they humiliated and kicked him and left his body," he said, showing video footage he had filmed then uploaded to a laptop with him in the camp.

"Its becoming like this all the time, we don't expect anything different tonight," he added.

Camp danger

Kilis Governor Yusuf Odabas told reporters two days of clashes had killed three people and injured 25. If fighting continued, the authorities would step up security and close the camp, he said.

But refugees, who were previously able to leave the camp freely if accompanied by a Turkish minder, said access to and from the site was now much more tightly controlled.

Outside the tall metal barriers surrounding the camp a dozen women and children lay on blankets with bags of clothes. They said they had moved from another camp at Reyhanli to try and join their families at Kilis.

"Now we are stuck, we don't know where to go. Most of our family is already in Kilis so we will wait here. I don't care about the fighting I want to be with my family. If we can't move where will we go, back to Bashar?" said one woman.

Syria has promised to observe a UN-backed ceasefire starting on Thursday, but its forces kept up fierce attacks on opposition neighbourhoods in the hours before the deadline.