Attack on the rally by gunmen also killed a schoolboy and injured at least five others on the scene.

"We have attached the property of four key suspects -- brothers Nurul Islam Dipu, Shahidul Islam Shipu and Ohidul Islam Tipu and Kana Hafiz -- and low-profile accused Jahangir to compel them to surrender," said Khalequzzaman, assistant superintendent of the Criminal Investigation Department (CID) of police.

Asked why the property of only five was attached when a case was filed against 18 suspects, Khalequzzaman, who is currently probing the case, said: "It's a primary step, we will also seize the property of some others, if need be."

The CID on Tuesday night arrested four Tongi youths believed to be associates of the killers of Ahsanullah, executive president of Awami Shramik League, the labour front of the main opposition Awami League (AL).

Hundreds of local residents gathered as a four-member CID team attached the property in Gopalpur and Morgon villages in the presence of a magistrate as paramilitary Bangladesh Rifles and Tongi police guarded the areas in force.

The CID arrested Nasiruddin, Suman, Oli and Qaiyum from Tongi to extract information on the whereabouts of the accused on the run.

"I've information that the four were close associates of some of the killing suspects. They're also involved in drug-pushing in the area for a long time," Khalequzzaman said.

"They may give accurate information on the killers and their whereabouts."

The First Class Magistrate's Court in Gazipur yesterday remanded the arrestees in six-day police custody.

MOURNING RALLY
Hundreds of people gathered at Gazipur yesterday to attend a rally organised by Gazipur Awami League at its office to mourn the death of the slain lawmaker.

Over 2,000 police guarded the rally, addressed by Ahsanullah's younger son Zabid Ahsan Sohel, frontline AL leaders including Motia Chowdhury, Obaidul Kader, Amir Hossain Amu, Giasuddin Manna and Mukul Bose with AL Gazipur unit president Mozammel Haq in the chair.

AL's Tongi unit will also hold a similar rally there on May 17 and another at Gazipur district headquarters on May 20.

Jatiya Shramik League organised a milad mahfil at its office in the capital yesterday, praying for the peace of the soul of Ahsanullah.

Ahsanullah's younger brother Motiur Rahman Moti who filed the first information report (FIR) told The Daily Star yesterday that police were arresting innocent people while the killers went scot-free.

"Today they arrested Palash, a poor scrap metal trader, who tried his best to save my brother in the wake of the shootout," Moti said.

"Police have arrested no-one of the killers five days into the killing. They are busy with harassing people who tried to save my brother and now demanding trial of the perpetrators," he alleged.

"Police say they don't know the whereabouts of the killers. I would ask them to arrest Nurul Islam Sarker," he said, accusing him of masterminding the killing.

Local residents alleged police picked up over 200 innocent people including AL adherents, but Nur Ahammad, officer-in-charge of Tongi Police Station, said the number was not more than 60.

"We've arrested about 20 people in different cases of vandalising BNP offices, vehicles and trains and 40 others on suspicion," he said.

GRAVE UNDER GUARD
Ahsanullah's relatives and AL workers are guarding the lawmaker's grave at Hyderabad village in Tongi round the clock after threats by the killers to snatch his body from there.

The killers have been threatening the slain lawmaker's relatives over phone since the killing to dig out his body unless they withdrew the case.

Meanwhile, the condition of Jubo League activist Mahfuzur Rahman Mahal, who is being treated for bullet wounds at the Combined Military Hospital, remained unchanged yesterday.