But police declined to divulge political identity of the three persons arrested under Section 54 of the CrPC on Wednesday. Their family members however told The Daily Star they are involved with the BNP and its affiliates.

Two of the arrestees -- Shah Alam and Jainal Abedin Jalal -- have been placed on an eight-day remand and are being questioned in the custody of the local detective branch. The other -- Abdul Wahed Sohel -- was sent to jail on Wednesday as police did not seek his remand.

Another BNP activist, Jainal Abedin Momin, was picked up Monday from Baidderbazar. He is still in police custody.

Investigators are tight-lipped about the outcome of their quizzing Shah Alam and Jainal so far.

"We have arrested these three persons under Section 54 for suspicious movement, and not in connection with the two cases (on the Habiganj carnage)," says Deputy Inspector General of Police of Sylhet Range AKM Mahfuzul Haq.

"We have got a lot of information about those involved in the incident. We are now verifying the information," he adds without elaborating.

The law enforcing and intelligence authorities declined to give the number of people picked up for questioning since the January 27 grenade attack. But one source said 18 people have been picked up so far.

The families of the three arrestees are in the dark about their whereabouts. They did not know till last night that one of the three was sent to jail and two others were placed on remand.

On Saturday at 2:00am, a team of Rapid Action Battalion (Rab) raided village Shughar in Lashkarpur union to arrest Shah Alam (32). Sine he was not at his house, Rab members first took his father Salamat Ali to Alam's sister's house at Chunarughat and then to his father-in- law's house in Matail village in Nabiganj.

As Alam was not found also at these houses, Rab released his father on condition that he will hand him (Alam) over to Rab if he finds him.

Alam's sister Jahanara Begum and Jasmin Ara Jui told The Daily Star that following the grenade attack, Alam slept at home, participated in the funeral prayer for the bomb victims of Bangaon village. Their father took him to Habiganj Circuit House Saturday afternoon and handed him over to Rab. Since then they do not know anything about him.

They said Alam is a BNP leader in Lashkarpur union but they do not know his rank. "No-one can say our brother Alam is a bad person," said Jahanara. "His only bad habit is wasting father's money."

They however said Jainal Abedin Momin is "pugnacious" and lives in Baidderbazar close to the grenade attack spot.

Momin's house is located only about 150 yards off the grenade attack spot. Residents of his house said Momin is the secretary of second ward committee of Lashkarpur union. He is also involved with the Zia Gabeshana Parishad.

"Our whole family supports Awami League but Momin supports BNP," said his brother, school teacher Jashimuddin Ahmed.

Momin, 27, is also a peon at Baidderbazar Post Office.

His mother, uncle and other family members said that Rab and intelligence men picked him up from in front of a shop in Baidderbazar Saturday afternoon.They suspect that since Alam was arrested earlier, may be Alam gave his name to Rab.

Alam is a "criminal" and he had enmity with Momin, they alleged.

Like Alam's family, they are also in the dark about Momin's whereabouts.

"If Momin is involved in such a heinous act, we will not try to save him. But if he is not involved in it, Allah will save him. That is why we did not try to get information about him," his brother said.

Jainul Abedin Jalal, 29, lives in the nearby Abdabkai village. His family members told The Daily Star that detectives picked him up Monday evening from a pharmaceutical shop he owns.

"On Tuesday, my father and uncle looked for him in many places, including Habiganj Circuit House," said his wife Sumi. "But they could not trace him till today."

She said her husband was a BNP supporter, he was not actively involved in politics. " He was busy in construction work at our house on the day of the grenade attack," she added.

Abdul Wahed Sohel,22, who was arrested and sent to prison, lived in Gopaya village of Gopaya union. His father Ashid Ali said, "Wahed is not involved in politics. He looks after a fodder shop I own."

Wahed was staying at his father-in-law's house at Chunarughat on the day of the grenade attack. He returned home on Sunday, and Rab picked him up at night, Ashid said.

Wahed's father, brother, sister-in-law and sister alleged Rab members beat him while taking him away. At one stage, Rab tore his shirt and blindfolded him with it.

There are two portraits of late president Ziaur Rahman and Prime Minister Khaleda Zia in Wahed's room.

His father wept and said he went to Habiganj Circuit House, thana and other places but could not know the whereabouts of his son.

Explaining why police are tight-lipped about arrestees and detainees, a police source said, "This is being done in the interest of proper investigation."

Asked why they were not being produced before court within 24 hours of detention, he said, "Many are dying following arrest but they are rather being treated well."

Detectives handed the three arrestees over to Sadar thana police on Wednesday.