Four years after a crude bomb-making operation went catastrophically wrong in West Bengal's Howrah district, the National Investigation Agency has arrested the two men it believes were running it.

Asfar Middya and Entajul Middya, both residents of Amta, were picked up on Tuesday following searches at three locations linked to the suspects. The NIA identified them as the prime accused in the February 23, 2022 blast near Chandrapur Bazar, under the limits of Amta Police Station, in which one person was killed and three others were seriously injured.

According to investigators, the two men were allegedly directing the illegal manufacture of crude bombs at the site when several of the devices exploded during the production process. The blast seriously injured Jahadhar Mollah, Mohabbat Mollah, Moinur Rahaman, and Sk Maharam. Maharam later died from his injuries.

The NIA took over the investigation from local police in April 2024. Probe findings suggest Asfar and Entajul were not just present at the site but were in control of the operation — and that the bombs being manufactured were intended to intimidate and terrorise people in the area.

Four other accused in the case had already been arrested and charge-sheeted earlier, with the case registered as RC-08/2024/NIA/DLI. The agency said Tuesday's arrests mark a significant step forward, but the investigation into the wider conspiracy is continuing. Authorities have not ruled out the involvement of additional persons.

The Amta blast was among several incidents in Bengal's Howrah region that drew attention to the presence of illegal bomb-making networks operating at the grassroots level. The pattern — crude explosive manufacturing in residential or semi-rural pockets, often tied to local political intimidation — has been a recurring concern for both state and central agencies in West Bengal.

With the prime accused now in custody, the NIA's focus is expected to shift toward mapping the supply chain and establishing who the bombs were ultimately meant to serve.