An online video that appeared to show teenage girls savagely beating younger pupils at a remote Siberian boarding school for orphans has sparked a criminal investigation and calls for public oversight over the government’s opaque and widely criticized orphanage system.

Children’s rights advocates said the incident should prompt lawmakers to pass a long-stalled bill that would allow designated members of the public to perform snap inspections of such facilities and give full access to the country’s 3,500 state-run facilities.

The video was also a reminder of the problems that still plague the state system months after the government banned U.S. adoptions, citing concerns about safety and accountability, and pledged to improve orphans’ wellbeing back home.

Investigators on Friday opened a criminal case into allegations that two teenage girls, pupils at Boarding School No. 5 in the Amur region, regularly tortured younger pupils over a four-month period ending this month, when scandalous images of a beating appeared on the Internet.

The girls, both adults by law,“systematically” beat pupils aged 7-10, investigators said. A third girl who participated in the beatings is not legally an adult, and law enforcement is looking into the actions of a fourth, who they believe recorded the video, investigators said in a statement on Friday.

The video, posted on the Amur.info news portal on Thursday, opens with one of the girls lining up several boys in their underwear against the wall and beating them one-by-one with what appeared to be a belt as the boys wail and writhe in pain.

If convicted of torture, the girls face a maximum of three years in prison.

Three teachers at the school, located in the village of Pionersky, about 190 kilometers northeast of the Amur regional capital of Blagoveshchensk, and the director — herself a former pupil — have been fired in connection with the allegations, investigators said.

Boris Altshuler, head of Rights of the Child, a watchdog, said it was nearly impossible to say whether the Amur case is an isolated incident because the system lacked transparency.“These institutions are virtually closed [to the public]. One doesn’t set foot in there,” he said by telephone Friday.

Russian law allows certain members of the public to make unannounced visits to prisons and interview inmates, but not orphanages, which are monitored exclusively by officials who have little incentive to root out abuse and corruption, he said.

A bill establishing public oversight of state orphanages received preliminary approval in the State Duma last spring, but later disappeared from the agenda after President Vladimir Putin said in February that parts of it and other related bills were ambiguous and carried “overt social risks.”

“Most importantly,” he continued,“they in no way fully take into account Russian family traditions.”

Putin had ordered the government to complete work on the public oversight bill and take other steps to improve the country’s adoptions and orphan welfare systems in December, the same month he signed into law a ban on U.S. adoptions that drew howls from children’s rights leaders.

The same presidential order gave governors responsibility for children in state care in their region.

Former children’s ombudsman Alexei Golovan, who warned against making generalizations about conditions in the nation’s orphanages, said public oversight could help prevent abuses like the Amur beatings.

“This incident should be an impetus to pass this law as soon as possible,” he said.

Current ombudsman Pavel Astakhov said he welcomed additional public oversight in general, including unannounced checks by designated members of the public, but he also variously suggested that it would be redundant, restricted and only partially effective.