Damascus, Syria (CNN) -- Amnesty International is accusing the Syrian government of torturing wounded protesters at state-run hospitals, saying the country's authorities have effectively turned medical facilities and their staff into "instruments of repression."
The London-based human rights group said in a report Tuesday the siege at government hospitals is a new, troubling trend in the efforts by the country's security forces to crack down on months-long protests against President Bashar al-Assad's regime.
"It is deeply alarming that the Syrian authorities seem to have given the security forces a free rein in hospitals, and that in many cases hospital staff appear to have taken part in torture and ill treatment of the very people they are supposed to care for," said Cilina Nasser, a researcher for Amnesty's Middle East and North Africa division.
Wounded protesters told CNN in July that they are scared to seek treatment at government-run hospitals, fearing arrest and torture.
"Given the scale and seriousness of the injuries being sustained by people across the country, it is disturbing to find that many consider it safer to risk not having major wounds treated rather than going to proper medical facilities," Nasser said.
Syrian officials have said the demonstrators' fears are unfounded and have denied allegations that the wounded are being targeted.
"We accept all cases without regard as to how the injuries were sustained or where it happened," Adib Mahmoud, the director general of Damascus Hospital, said in July.
Amnesty said instances of abuse have been found in at least four state-run hospitals. One doctor at the military hospital in Homs told the group he witnessed more than two dozen members of the staff, including doctors and nurses, mistreating patients. Security forces have also raided the facilities, arresting some of the wounded.
"Afraid of the consequences of going to a government hospital, many people have chosen to seek treatment either at private hospitals or at poorly equipped makeshift field hospitals," according to Amnesty's report.
On the backstreets, on concrete floors, in secret locations, an underground network of doctors have stepped up to try to treat wounded victims. They call themselves the Damascus Doctors.
The group set up a field hospital with basic supplies this summer in a secret location.
"They refuse to go to the government hospitals because they will be arrested and if they die we cannot take their body," the founder of Damascus Doctors, whom CNN is not naming for safety reasons, told CNN in July.
Similar underground clinics have been established elsewhere in the country.
The unrest in Syria began in mid-March and has continued, despite a crackdown by government forces. At least 3,000 people have died, the United Nations and other international observers estimate.
As the crackdown intensified, demonstrators changed their demands from calls for freedom and an end to abuses by the security forces to calls for the overthrow of President Bashar al-Assad.
The founder of the underground doctor network said he has been touched by the resolve of the wounded protesters.
"Sometimes I feel bad when I see people shouting for their freedom," the founder said. "Even when I am making the sutures to their muscle, tendon or their skin, they keep shouting for freedom. They say, "We want our freedom. We will keep fighting.'"