But President Pervez Musharraf stressed that the situation did not warrant the imposition of Emergency.

Pakistan ordered extra troops into Karachi Sunday as deadly violence over the suspension of the country's chief justice spilled into a second day, raising the death toll to 37.

Three people including a policeman were the latest victims as protesters blocked the main highway with burning tyres and pelted vehicles with stones. Karachi police chief Azhar Farooqi described the situation as "very tense."

"The assailants set his bike on fire and tortured him before shooting him from close range," said police officer Shafiqur Rehman, referring to his dead colleague. Two other men were shot dead in separate incidents.

Heavy gunfire was also heard in the southern port city's impoverished Banaras Chowk area, where angry protesters beat up four policemen. Police used tear gas to clear the roadblock on the main highway.

Amid heavy gunfire nearby, a mob set ablaze around eight bamboo shops of rival groups after prayers at the funeral of a violence victim in Karachi's Federal-B area, but paramilitary troops and firefighters stopped the fire.

The funerals of two other casualties went ahead peacefully near the tomb of Pakistan's founder Muhammad Ali Jinnah.

Opposition parties observed a "black day" on Sunday over the Karachi killings and held protests in several Pakistani cities.

Activists burnt an effigy of Musharraf in central Multan city with calls that he should resign.

Musharraf, who addressed a pro-government rally attended by some 35,000 people in capital Islamabad late Saturday, condemned the unrest but laid the blame on Chaudhry and also on the opposition for impeding his supporters in Karachi.

'The main reason for what happened today in Karachi is that a judicial matter was politicised,' said Musharraf, who suspended the judge for alleged abuse of office on March 9, triggering a wave of protests.

'People are with me,' he asserted.

However, he said the situation did not warrant imposition of emergency. The opposition parties disagreed, saying the president was in fact working towards it.

On Saturday, Chaudhry was set to address a rally in Karachi but workers of the pro-government party Muttahida Qaumi Movement (MQM) exchanged fire with opposition activists. MQM's rally in Karachi had been planned on the same day.

Mobs armed with assault rifles and shotguns fought pitched battles in the streets and torched at least 40 buses and cars. The government and opposition blamed each other for the violence, the Daily Times said Sunday.

Justice Chaudhry remained stranded at Karachi airport after flying in because government supporters had used trucks with deflated tyres to shut down all main roads. He returned to Islamabad later.

In Karachi, the vast Shahra-e-Faisal area from Baloch Colony Bridge to Malir 15 turned into a war zone even though rangers and police were present.

'They (police) did not interfere,' the newspaper said. It quoted a low-ranking policeman at Shahra-e-Faisal, carrying only a baton. 'There were some orders and our weapons were taken from us. It was as if we were put here just to watch.'

Despite the deployment of 15,000 police and paramilitary troops, shooting continued through the day and city hospitals struggled to cope with the flow of dead and wounded, health officials said.

Gunmen also attacked the Aaj TV building forcing the staff to remain indoors. Firing started shortly after the station aired footage of fighting between the MQM supporters and Baloch and Pashtun groups opposing them.

'We are under attack,' Aaj TV Director of News Talat Hussain said on air as he sheltered behind a wall. 'No one has come to help us,' he said.

Journalists were also beaten up at Karachi airport. Security personnel broke camera equipment belonging to six media persons.

The rally of MQM, a party dominated by migrants from India who went to Pakistan after partition in 1947, was 'thinly attended,' media reports said. Its chief Altaf Hussain, who is exiled in London, addressed it over telephone.

Hussain claimed that his supporters' rally had been peaceful and the situation had deteriorated only when Chaudhry arrived in Karzachi.

He held Chaudhry responsible for the deaths that had been caused and demanded that he apologise to the nation 'for taking judicial matters onto the streets'.