Two people, including a former union parishad chairman, were killed in "gunfights" with law enforcers in Bagerhat and Bandarban early yesterday.
In another incident, an alleged drug paddler was killed in "infighting" in Satkhira.
In Bagerhat, Mostafa Kamal alias Mina Kamal, 58, a former chairman of Naihati Union Parishad in Khulna's Rupsha, was killed in a "shootout" with Rab members in Rampal upazila.
Lt Col Raushanul Firoz, commander of Rab-6 in Khulna, said they went to Babu Bari area near Rampal Thermal Power Plant on information that a secret meeting of drug dealers was going on there.
Sensing the presence of Rab members, the criminals opened fire. Rab members retaliated, triggering the "gun battle", he said, adding that at one stage, Mostafa was caught in the line of fire, while others fled.
The injured was taken to Jhanjhania Hospital in Rampal where doctors declared him dead.
Rab claimed to have recovered a foreign pistol, 500 yaba pills, a knife, and Tk 67,000 from the spot.
In Bandarban's Naikhyangchhari upazila, an alleged Rohingya drug peddler was killed in a "gunfight" with police.
Shah Alam, 45, was a resident of Ukiya Rohingya camp, said police.
"We arrested Shah Alam on Wednesday night and took him to Ghumdhum area, near Myanmar border, around 3:00am to recover drugs," said Alamgir Hossain, officer-in-charge of Naikhyangchhari Police Station.
The OC said sensing their presence, his cohorts opened fire. Police returned fire, triggering the "gun battle". Shah Alam was hit by bullets when he tried to flee from the police custody. He died on the spot, the OC added.
Police claimed to have recovered 40,000 yaba pills, a firearm, and three bullets from the spot.In Satkhira, a drug peddler was killed when two groups of drug dealers were exchanging bullets in Bashdaha Koiarbeel area of Sadar upazila, claimed police.
Liakat Ali Sardar, 45, of North Taluigacha village of the upazila, said Asaduzzaman, officer-in-charge of Sadar Police Station.
In another incident, a suspected bidi smuggler was killed as BGB members opened fire on his gang in "self-defence" in Moulvibazar's Kulaura upazila.
The dead is Badrul Islam, 22, of Daudpur village in the upazila.
Mohammad Abdul Kader, Alinagor camp commander of BGB-46 Battalion, said a BGB patrol team took position in Shuvonavi Char area near Razapur bridge on information that a big consignment of Indian Nasir Bidi would be smuggled in from India.
Sensing the presence of BGB team, the criminals attacked them with sharp weapons, the BGB official said.
The patrol team opened fire in "self-defence" and to disperse the smugglers, he added.
The BGB official said after they returned from the spot, locals informed them that a bullet-hit body was found on the spot.
[Our correspondents from Bagerhat, Bandarban, Moulvibazar, and Satkhira contributed to this report]