Dhaka: Two militants linked to the Islamist extremist group behind July's Dhaka cafe siege that left 22 people dead were killed Saturday after Bangladesh police raided a hideout in the capital, officials said.

Security forces, acting on a tip, besieged a flat in Dhaka's Dakshinkhan neighbourhood for more than 12 hours, with the operation coming to an end at around 4.00 pm (1000 GMT) after officers exchanged gun-fire with the militants, police said.

A child was also injured when one of the militants, a woman who was holding the child, exploded a vest she was wearing.

One of the deceased was wife of absconding militant Sumon while another was 15-year-old Afif Kaderi, son of Tanvir Kaderi, who was killed in Azimpur raid in September last. The injured was a seven-year-old girl, daughter of slain militant Iqbal.

Besides two other women -- Jebunnahar Shila, wife of ex-army Major Zahid, who was killed in a 'gunfight' with law enforcers at Roopnagar in the capital on September 2 last, and Trishna, wife of absconding JMB leader Musa --- along with two children surrendered to police.

Tipped off that some 'Neo-Jamaatul Mujahideen Bangladesh (JMB)' members were staying at an apartment in a three-storey building of the area, a team of the Counter Terrorism and Transnational Crime (CTTC) unit cordoned off the building early in the morning, said Home Minister Asaduzzaman Khan Kamal while talking to reporters after visiting the spot.

Police asked the JMB members in the den to surrender but they did not respond to their call, said the minister.

Later, two female militants-- Shila and Trishna --and two children came out of the house at about 9:00am and surrendered to police, said Kamal.

Following repeated requests to surrender, another woman, wife of Sumon, along with the 7-year old girl came out of the house and blasted a bomb at the gate around 12 pm, leaving the woman dead on the spot and the minor girl injured.

Later, the CTTC team rescued the girl and took her to Dhaka Medical College Hospital (DMCH).  

At about 2:00pm, when the law enforcers tried to enter the flat, Afif Quaderi opened fire towards them, prompting them to retaliate, he said.

At one stage, a bomb got blasted being hit by bullets during the gunfight, leaving Quaderi dead on the spot.

Quaderi was found lying on the floor after the gunfight, said the minister adding that police did not enter the house to recover the body as there might have more powerful bombs near the body, said the minister.

Bangladesh has been reeling from a wave of attacks on foreigners, rights activists and members of religious minorities.

Prime Minister Sheikh Hasina's secular government blames local militant groups like JMB for the carnage, rejecting claims by the Islamic State group and Al Qaeda.

Since the July massacre, security forces have shot dead nearly 50 Islamist militants including a Canadian of Bangladeshi origin who was accused of masterminding the restaurant attack.