Police in eastern Pakistan say they've arrested seven men accused of sexually abusing children and distributing videos of the abuse.
Kasur district regional police chief Shahzad Sultan said on August 9 that investigators were sifting through evidence, including 18 or 19 videos seized so far.
It was not yet known how many children were abused or if there were other videos.
Police said about 10 other suspects would be arrested soon.
The allegations became public after victims' families clashed with police on August 4, complaining the authorities were ignoring their cases.
Over 20 people were injured in the clashes on August 4, when police used force to disperse more than 400 protesters.
Child Protection Bureau chief Saba Sadiq has demanded a high-level judicial probe, while provincial chief minister Shahbaz Sharif ordered investigators to make all the facts public.
Analysts say individual cases of child sexual abuse are not a rarity in Pakistan, but the current case may be the first involving allegations of organized abuse.
Police were investigating claims the suspects were blackmailing the victims' families, demanding money in exchange for not making the videos public.
Copies of the abuse videos were allegedly sold in local markets.
According to local media, most of the children were below 14 years of age and were residents of Husain Khanwala village, near Kasur.
A local gang began filming sexual exploits with the children in 2006, which allegedly continued until last year.
The victims were forced to have sex, and the videos were then circulated for 50 rupees (about $0.4).
"They made the video of my son in 2011 and we have been paying the blackmailers since then," the mother of one of the victims, who did not want to be named, told an AFP reporter.
In an initial report ordered by the Punjab provincial government last week and carried out by police, local authorities described the allegations as "baseless."
It was rejected by media and rights activists who said the officials carrying out the inquiry were biased.