The Rapid Action Battalion (RAB) arrested Jamalpur's Sadhurpara Union Parishad (UP) Chairman Mahmudul Alam Babu, the prime accused in the murder of journalist Golam Rabbani Nadim, on Saturday morning, three days after the incident.

Babu is also the union Awami League's general secretary.

A team of RAB-14 made the arrest around 7am from Char Tistapara, a bordering area in Panchagarh's Chilahati union under Debiganj upazila, RAB Legal and Media Wing Director Khandoker Al Moin told media today. 

The other arrestees are: Rezaul, Monir and Zakir. 

RAB claimed that the three directly took part in the murder, alongside other members of Babu's gang. They were arrested from Bogura and some other parts of the country. 

"Journalists are sometimes being attacked for doing their job. Journalists are friends of ours [RAB] in the fight against terrorism and criminals. No one is above the law, and we always try to ensure justice when the journalists are being attacked in the line of duty," Khandoker Al Moin said. 

"Nadim had recently reported on corruption and irregularities of Babu, which made him angry. He planned the murder to teach a lesson. Babu planned and was directly involved in the murder," Khandoker Al Moin said. 

"Nadim posted a status on the same day when the DSA case was dismissed against him. This made Babu angrier. He gave orders and orchestrated the killing from behind the scene. Monirul and Zakir, his gang members, were also accused in previous other cases," said the RAB director. 

After news of the murder broke, Babu went into hiding in a relative's house in Pachagarh's Debiganj. He left behind his mobile phone so he could not be traced. 

His son, Fahim Rahman, alias Rifat, another accused in the case, is still on the run. 

According to the RAB, they are trying to nab him. 

Asked why law enforcement agencies had failed to provide security for the journalist, even though he had sought help in this regard in a social media post a few days before his murder, the RAB director said he had received no such written request.

"We don't know whether he made any complaints to the police station concerned. If he did, he would surely get legal help," said Khandoker Al Moin.