(CNN) -- A witness to the brutal massacre in the Syrian town of Houla which left more than 100 people dead, many of them women and children, says he fears the killing will continue unless the international community takes action.
"We are human beings, not animals," Mahmoud Al Houli told CNN by telephone. "I would like to call for the international community and the U.N. to save our souls, to help us find a solution. We only want freedom."
He said conditions in Houla were "desperate," with medical supplies and food running low, and a build-up of military personnel in the area leaving residents dreading a second wave of attacks.
"We are very afraid that there will be another massacre," Al Houli added. "Military reinforcements have been brought in, and artillery, and we are afraid that the massacre will happen again."
On Tuesday, a United Nations official said it was "clear" that Syrian government forces were involved in the slaughter last Friday, which he said was "an abominable crime."
Rupert Colville, a spokesman for the U.N. human rights office, said the majority of victims died as a result of "summary executions" in which "armed men... went house to house, killing men, women and children."
Syria has denied responsibility for the massacre, which it insists was carried out by "terrorists." Countries around the world have expelled Syrian diplomats in protest at the killings.
But Al Houli said more needed to be done to prevent further tragedy.
"The situation here is very bad, very, very bad. There is a severe shortage of medical supplies in the local hospitals. Lots of people were injured, but there is a shortage of supplies to treat them with.
"Four checkpoints have been set up around the town, and nothing can enter -- no food or medical supplies can come in. The electricity has been cut off. Things are desperate."
Al Houli told CNN he was at a protest rally in the town on Friday when members of the military opened fire.
"We had a demonstration after Friday prayers, and all the men were there," he explained. "The military started shooting at the demonstration."
"After that, thugs from the regime came from the surrounding towns, to make a big massacre.
"While the men were at the demonstration, they attacked the women and children with knives and machine guns."
He said he believed the men who carried out the attack were trying to incite a sectarian conflict in the region.
"Many civilians were killed. I saw the bodies of women, children killed by knives -- I still have the image in my eyes.
"The bodies were taken to the mosques, because there were so many, there was nowhere else to put them.
"You have seen the bodies on television, on the computer, but we see them in real life."
As he spoke to CNN, a voice boomed from a loudspeaker nearby. "Another person has died," he explained. "They are making the announcement at the mosque."
Al Houli was clear who he held responsible for the tragedy in Houla. "[President Bashar al-]Assad is a killer of children and women.
"He needs to leave Syria and get out of the country -- that's the best solution.
"If he leaves, we can go back to normal life."
CNN's Kindah Shair contributed to this article.