The report comes amid an international outcry over a cease-fire violation by the government and opposition forces.
"All the parties need to take further steps to ensure a cessation of violence in all its forms," said Herve Ladsous, the U.N. under-secretary-general for peacekeeping, on Tuesday. "The people of Syria have suffered too much."
But the presence of the tiny but growing U.N. observer team is having a "dampening effect" on the violence, Ladsous said.
Twenty-four unarmed military observers are in the country, and the number will rise to 300 by the end of the month, he said Monday. The observers are in Homs, Hama, Daraa, Idlib and Damascus.
Human Rights Watch urged the United Nations to ensure its monitoring mission included a human rights staff to interview victims of abuses and protect them from retaliation.
"The peace plan efforts will be seriously undermined if abuses continue behind the observers' backs," Neistat said.
Meanwhile, violence continued.
At least 30 people were killed Wednesday, including defecting soldiers and a woman, the opposition Local Coordination Committees of Syria reported.
Ten of those deaths occurred in the northwestern Syrian city of Aleppo, said Mohammad Said Hareitan, a 25-year-old English student at Aleppo University. It was there that four students were killed and 50 wounded when police and soldiers fired Thursday morning on an anti-government demonstration, he said.
Gunfire resumed at the hospital where many of the wounded were taken, with more casualties resulting, he continued in a telephone interview with CNN.
In the north of the city, another six people were killed, he said.
A day earlier, regime forces killed at least 48 people, the network of opposition activists said.
Syria's protests started peacefully in March last year, but a government crackdown spawned violence that has left thousands dead and prompted some military defectors to take up arms against the regime forces.
The United Nations estimates that at least 9,000 people have died in the conflict while opposition groups put the death toll at more than 11,000.
President Bashar al-Assad's family has ruled Syria for 42 years.