The news released by a Bangladeshi private news agency from Guwahati said Ulfa commander Pallav Saikia confessed that his group was behind the attack on the AL rally at Bangabandhu Avenue in 2004.

The new claim has created controversy and raised questions about its authenticity. It also contradicted a few previous disclosures made by the local investigators since the attack, which killed 23 including Awami League (AL) women affairs secretary Ivy Rahman.

Judicial confessions of Joz Mia, Shafiqul Islam Shafiq and Abul Hashem Rana in 2005 linked top criminals Subrata Bain, Khondoker Tanvir Islam Joy and Molla Masud along with others.

A Harkatul Jihad (Huji) operative also claimed last year that the Islamist militant group was behind the attack.

Demand has been made in the wake of the new situation for a neutral and fresh investigation of the incident as investigations are often made with political bias.

"We have not yet found any clue that goes with the Ulfa claim," said Criminal Investigation Department (CID) Assistant Superintendent Munshi Atiqur Rahman, who has been involved in the investigation since the attack.

"We do not know the authenticity of the news as the Ulfa itself has denied its involvement in the attack," he said, adding that the investigators may go for fact-finding following government orders.

The Bangladeshi news agency on Saturday quoted the chief of special branch of eastern Indian state Assam, Khagen Sharma, as saying that Pallav confessed to attacking the AL rally at the "explicit instructions" of Ulfa military-wing chief Paresh Barua.

A few Bangladesh intelligence officials helped the Ulfa plan the attack and even provided 11 Ulfa men with vehicles on August 21 morning, Sharma said, adding that he does not know the identity of those officials.

Bangladeshi newspapers and television channels carried the news with utmost significance.

A Bangla national daily reported that former National Security Intelligence (NSI) chief Maj Gen Rezakul Haider Chowdhury assisted the Ulfa in carrying out the attack on August 21 and Jama'atul Mujahideen Bangladesh (JMB) later in raising bomb attacks.

Meanwhile, Ulfa Chairman Aravinda Rajkhowa yesterday denied his party's involvement in any attack in Bangladesh.

A CID official yesterday said they do not totally brush aside the possibility of Ulfa involvement in the attack and will try their best to verify the information.

Home Secretary Abdul Karim yesterday said he asked for information in this regard from the Bangladeshi intelligence agencies and the foreign ministry. "We will decide what to do after we get the information," he told reporters at his office.

Meanwhile, questions like who plotted the attack, what was the attack's motive, who supplied the grenades, how the same type of grenades were sneaked into Dhaka Central Jail, why the evidence was destroyed deliberately, and why two victims were buried hurriedly have remained unanswered although two years have passed since the grenade attack to assassinate AL chief Sheikh Hasina.

The government has not only shown lack of interest in bringing to justice those who carried out the grisly attack but is yet to clear why law enforcers totally failed to ensure security at the rally and arrest any of the attackers from the spot.

Although the government attempted to earn public acclamation by inviting the Interpol and US Federal Bureau of Investigation (FBI), it has failed to make any credible revelation into the mystery.

The investigators attempted to submit the charge sheet of the case over a year ago basing on the confessional statement of Joz Mia, but the government held them back following media flak terming Joz Mia's story very weakly-woven.

Twenty people were arrested after the attack but 17 of them were released as the allegation against them had "no merit". The rest three gave statements admitting their involvement in the attack.

The investigators are alleged not to have collected the pieces of evidence, including the unexploded grenades, which were vital for the investigation.

Army explosives experts detonated two unexploded grenades--one found near the spot and another at the adjacent Gulistan Hawkers' Market--in the dead of night without taking fingerprints on them. They carried out a similar detonation of another grenade recovered from the Dhaka Central Jail a day after the attack.

The mystery behind the quick burial of two unidentified victims on August 22 night has not been resolved.

The one-member government judicial inquiry commission of Justice Joynul Abedin linked a foreign enemy with the attack but his report was not made public. The government is yet to declare if there were any recommendations in that report and, if any, whether they were implemented.

The judicial inquiry commission claimed to have identified the perpetrators but its head declined to disclose their identity.

"The incident is a stark attack on the independence and sovereignty of the country," Justice Joynul Abedin had told reporters.