Police said driver Altu Mia was held at Alipur in Bahubal upazila, Kishore Dev Barman at Satchhari in Chunarughat upazila and Swapan Kumar Goala at Teliapara in Madhabpur upazila.

A truck with the similar registration number of the one seized at Dhupchachia along with the rifle bullets and explosives was detected at Chunarughat.

Police raided the house of Ashish Dev Barman, owner of the truck, who was not in. Driver of the truck Altu Mia was taken into custody from his house in Teliapara at about 11:30pm.

In another raid police arrested Kishore and Swapan from their houses at Satchhari and Teliapara.

All of them were handed over to detective police in Dhaka yesterday for interrogation.

Our staff correspondent Anwar Ali from Bogra reports: Police investigators have claimed that the probe into the biggest ever ammunition and explosives haul is 'over'.

A police investigator told The Daily Star, "The only task of police now is to find out the culprits."

Meanwhile, police picked up four persons and produced them before a first class magistrate's court to record their statements under Section 164 as witnesses of the cases filed in connection with the incident.

One of the four persons is Samad, the rickshaw-van puller, who was hired for unloading the ammunition and explosives from the truck.

The rest three are Birkadar Union Parishad member Abdul Hamid, Abdur Rashid and Ashraf Ali. All of them are local BNP workers.

Local Jamaat-e Islami of Bangladesh (JIB) allegedly threatened two journalists for reporting that JIB workers were arrested in connection with the ammunition and explosives haul, sources said.

The journalists are Abdur Rouf Jalal, Bogra correspondent of the Channel -i and Iqbal Morshed Ripon, Bogra correspondent of the ATN Bangla.

They reported that arrestees Delwar Hossain and Shamim were activists of the JIB and its student front the Islami Chhatra Shibir in their evening news bulletins on Sunday. A group of more than 12 persons led by Majedur Rahman, former president of the town Chhatra Shibir, threatened Abdur Rouf Jalal and asked him to send a 'corrected report' by 10:00pm Sunday stating that the arrestees were Awami League workers.

At around 12.30pm yesterday, police intercepted Iqbal Morshed Ripon while he was returning home and reportedly kept him confined for 90 minutes at the SP's office and he was interrogated by the Deputy Inspector General (headquarters) Shahadat Hossain.

The ATN Bangla and the Channel-i in their late night bulletins Sunday described the three arrested men as AL workers.

Meanwhile, Delwar Hossain told The Daily Star at the thana custody yesterday that he had been a JIB worker since 1984 and recently he vied for the 'rokon' post of the party.

Another arrestee Shamim, who was identified as a Shibir worker, denied having any link with politics.

Police recovered 62,112 Chinese rifle bullets and 120kg of explosives from an abandoned truck and Awami League leader Sayed Akhlakur Rahman Pintu's house at Jogarpara village under the Kahalu Police Station in Bogra Friday night.