Before setting off the suicide explosions on Thursday in Godagari Upazila, they launched an attack on police and fire service personnel, spearing a fireman to death, said police.
As many as seven policemen were injured, said Godagari police OC Hifzul Alam Munshi.
Police identified those killed as Sazzad Hossain, his wife Beli, daughter Karima, and sons Alamin and Shoeb. Sazzad was the owner of the house.
The women were seen using machetes and another man using a spear. Among those injured, a fireman Abdul later succumbed to his injuries.
Later, they exploded suicide vests, according to law enforcers.
Sazzad's other daughter Sumaiya was spotted sitting on the field outside the house when the security personnel were being attacked.
Police initially suspected Sumaiya to be wearing a suicide vest. She surrendered to police three hours later around 11am.
Locals at Benipur Village, some 30 km off the Rajshahi city, said the house in the middle of a field was built around two months ago.
Sazzad lived with his wife, two sons and as many daughters and the family avoided neighbours, according to villagers.
Sazzad used to sell clothes as a roving trader. His sons, Alamin and Shoeb were involved in farming.
Locals referred to house as 'Alamin's home', said Godagari OC Munshi.
"In the morning, we urged them to surrender, but at least two bullets were fired from the house."
The law enforcers then started preparing to storm the house. The fire service used their hoses on the house, after which the boy came out with his infant sister.
"Around 7:45am, some people came out from the house and attacked police and fire service personnel before setting off blasts. Five bodies were found on the spot afterwards."
Sub-Inspector Utpal, Constable Tajul Islam and Fireman Abdul Matin were rushed to the Rajshahi Medical College Hospital, where Matin died while being treated.
The other injured policemen have been given first aid, said OC Munshi.
Sumaiya's husband Zahurul hails from Godagari Upazila's Diya Manikchar, according to Towhid.
In March this year, law enforcers raided seven houses in Chittagong and Sylhet region, when 26 people, including women and children were killed.
From late April, raids have been conducted on five places in three districts of the northeastern region.
On Apr 20, police raided a house at a village near the Jhenaidah district town.
No one was found in the house of Muslim convert 'Abdullah', but police said they found explosives and bomb-making materials there.
A week later, police raided another militant hideout in Chapainawabganj, when four terror suspects were killed in suicide blasts, officials said.
The latest anti-terror raids occurred on May 7 on two houses in Jhenaidah. Two suspected militants were killed at one of the houses while police found firearms and bombs at the other place.
The spate of suicide explosions by terrorists have become now a familiar pattern whenever their hideouts have been raided.