GENEVA — Syrian government forces are systematically attacking hospitals and medical staff members and denying treatment to the sick and wounded from areas controlled or affiliated with the opposition, United Nations investigators said Friday in a new report that also detailed the use of hospitals as torture centers by military intelligence agencies.

“The denial of medical care as a weapon of war is a distinct and chilling reality of the war in Syria,” the United Nations Commission of Inquiry, which is monitoring human rights in Syria, said in its report. The panel said pro-government forces carried out such attacks “as a matter of policy,” but it also documented instances of attacks on hospitals by opposition forces.

The four-member panel said it published the findings two days after a broader report on war crimes in Syria to draw attention to what it called “an enduring and underreported trend” in the conflict. “By rejecting the irrefutable and universally accepted principle that those wounded in hostilities must be treated, the parties to the conflict in Syria are setting a dangerous precedent,” the panel warned.

The report cited a string of attacks on hospitals that were shelled by artillery or bombed by jets, often after aerial reconnaissance by helicopters. A public hospital in the northern city of Aleppo came under fire from helicopters and was hit by rockets and a missile strike. “These attacks injured and killed civilians receiving treatment in the hospital and medical personnel, significantly damaged the hospital’s infrastructure and substantially reduced its ability to treat patients,” the report said.