But officers investigating Thursday's deadly attack on policemen gathered in the commercial heart of Lahore said it was too early to determine who orchestrated the latest in a wave of suicide attacks that has rocked the country.

'It seems that the incident has links in the tribal regions and Thursday's blast was the handiwork of those who have carried out similar strikes in other parts of the country,' said senior police officer Aftab Cheema.

No one has claimed responsibility for the attack, in which a suicide bomber approached a group of about 60 riot police officers outside the Lahore high court and detonated a device packed with ball bearings.

Lahore police chief Malik Mohammad Iqbal said investigators were still trying to determine who the bomber was.

'We have found the head and legs of the bomber, but they are in very bad shape because he used high explosives,' he said.

'We are trying to establish his identity. We have sent his limbs for DNA tests.'

Police said earlier that the attack killed 26 people, but yesterday, they revised the toll down to 16 policemen and three passers-by.

The blast, which occurred two weeks after the assassination of opposition leader Benazir Bhutto, deepened fears of a bloody build-up to crucial elections on Feb 18.

Pakistani leaders, backed by their close allies in the United States, said the bombing was a clear attempt to sabotage the democratic process in the nuclear-armed Islamic republic.

The general election was postponed after Ms Bhutto's murder, and analysts said more attacks like Thursday's could force the date of the vote to be pushed back further.

'I think these attacks are meant to create anarchy and chaos before the election,' said former army general Talat Masood.

While Information Minister Nisar Memon had declared earlier that elections will be held as scheduled, others believe it will not take much to cause a further postponement.

Analyst Hasan Askari, former head of political science at Punjab University, said the election commission had created problems by citing, as a reason for postponing the vote, the burning of election offices in several cities during riots that occurred after the Bhutto killing.

Doing so 'sets a good precedent for troublemakers to destroy a couple of offices close to Feb 18 and get another postponement', he said.

General Masood noted that the fresh violence served only to underline the urgent need for a strong government.

'It reinforces the fact that elections are so necessary and you really need a representative government to tackle the situation,' he said.

'I am sure we are going to experience more such acts unless we take specific measures.'

AGENCE FRANCE-PRESSE, REUTERS