A pregnant woman in Noakhali's Senbagh was raped by a man and filmed by his associates on October 9, just five days after the Begumganj rape.
The video of the incident has gone viral in social media.
Meanwhile, another housewife was raped at knifepoint in the same upazila early yesterday, and two minor girls were raped in Satkhira since Tuesday.
The Senbagh victim, who was driven away by her husband after the incident, filed a case with Senbagh Police Station on Tuesday night -- 11 days after the incident -- against eight young men in the area, along with five to six unknown people.
Police arrested three accused including Shuvo, 18, Raki, 17, and Hasan, 18. However, they could not arrest Parvez, 25, the mastermind, reports our Noakhali correspondent.
The victim's husband worked as a microbus driver under one Shimul. The husband had gone to Chattogram for a trip on October 9, leaving his wife home alone.
Shimul's brother Parvez came to know about the woman being home alone and went there at night with 10 to 12 young men along with him.
As Parvez raped the victims, his associates, including Raki, Shuvo and Hasan, filmed through the window.
They later tried to blackmail the housewife with the video and demanded that she pay them Tk 30,000.
As she could not, they sent the video to her husband, who kicked her out of the house and went into hiding himself.
The family of rapist Parvez said the matter would be solved through "arbitration" and asked the victim not to file any case.
Meanwhile, the victim informed the Union Parishad chairman of Chhatarpaiya about the incident on Tuesday morning, but he did not take any step to resolve the matter.
The woman then filed a rape case with Senbagh Police Station on Tuesday night.
Tarequr Rahman, sub-inspector of the station, said there was one rapist and others filmed the incident.
"We have arrested three of them and are trying to arrest others, including Parvez."
The victim's husband remained in hiding since the incident, police said.
Another woman was raped at knifepoint in the same district early yesterday.
Quoting the victim, police said the 29-year-old woman is a wife of a Saudi-expatriate and a mother of two. She lives with her mother-in-law and children.
While she was sleeping with her children on Tuesday night, one of their neighbours, Mujibul Rahman Sharif, 32, entered her room early yesterday.
When victim started shouting, the accused showed her a sharp weapon and threatened to slaughter her children.
He then raped the housewife and filmed it. He threatened that he would release the video on social media if she did not have sexual relations with him again.
The victim filed a case against the accused yesterday noon, after which police arrested the accused, said Md Anwarul Islam, OC of Chatkhil Police Station.
Meanwhile in Satkhira, an eight-year-old girl was raped.
Quoting Fingri's victim's family members, police said a 13-year old boy, who the young girl was previously acquainted to, took the girl to a nearby garden and raped her.
The same night, the victim's mother filed a case against the minor boy, who was arrested, said Md Asaduzzaman, OC of Satkhira Sadar Police Station.
Contacted, the hospital's emergency unit doctor Tanvir Ahmed said they have found evidence of rape from the victim's body. Details would be known after completion of the medical tests.
(Our correspondents from Noakhali, Rangamati, Gazipur and Satkhira contributed to the report.)