Four persons were detained in connection with the gruesome killing of a police officer's wife in Chittagong, Home Minister Asaduzzaman Khan said today.

Superintendent of Police Babul Akter, husband of slain Mahmuda Khanam Mitu, filed a case against three anonymous people with Panchlaish Police Station in Chittagong today.

Chittagong Metropolitan Police (CMP) Commissioner Iqbal Bahar differed with the home minister's statement on detention of four persons in connection with the murder.

Bahar however admitted that police were quizzing four people at the moment.

This morning, police claimed they found the motorcycle that the killers used during the killing mission of Mitu. It was found lying abandoned on a street in the port city.

"It was a targeted killing," Home Minister Asaduzzaman said while briefing reporters.

"Targeted killings are being carried out everywhere in the world, no one is being able to stop them."

The home minister said that "combined efforts" were launched to ensure the security of the families of the law enforcers.

There have been no arrests so far in the incidents, our Chittagong correspondent reported. Police have CCTV footages and spotted three bike-riding suspects with one carrying pistol.

Mitu, wife of Babul Akter, was first hacked and then shot to death before her six-year-old son in broad daylight and near the populated GEC intersection in Chittagong city.

Many suspect that the murder was carried out to settle a score with Babul, who had a successful run in clamping down militancy in Chittagong with an iron fist.

Yesterday, the home minister was quick to blame militants responsible for the attack, saying they might have carried out the murder for her husband's expertise in curbing militancy.