'We will avenge your martyrdom, we will avenge your killing,' the young Islamic zealots chanted as they attacked cars and attempted to set fire to a cinema.

The bullet-riddled body of Tariq, a member of the National Assembly who led the banned militant organisation Sipah-e-Sahaba, or the Army of Prophet Mohammad's Companions, was later taken for burial to his hometown, Jhang, in Punjab province.

The bearded, mascara-wearing Tariq, 42, was among Pakistan's most feared radical Islamic leaders. His group is reputed to have killed at least 400 members of the minority Shi'ite sect during the last decade. Tariq was shot dead at a toll gate along with three armed bodyguards and his chauffeur while driving into the capital on Monday. Three unidentified gunman pumped around 90 bullets into his car, nearly half of which hit him, making it difficult for authorities to even identify his body.

Tariq was one of the founders of the Sipah-e-Sahaba, which wants Pakistan to be declared a Sunni Islamic state and the Shi'ites excommunicated as infidels.

His killing is expected to have serious political and security repercussions, as Sunni extremists take revenge against minority Shi'ites and intensify their opposition to President Pervez Musharraf's US-sponsored war against al-Qaeda and the Taleban.

In Jhang, police said a group of 50 to 60 Sipah-e-Sahaba activists attacked a Shi'ite mosque, but there were no casualties because it was empty at the time.

Already, with radical Islamic groups in power in the two Pakistan provinces bordering Afghanistan, there has been a resurgence of anti-Shi'ite violence this year.

Six Shi'ites were killed in the port city of Karachi last week, while earlier this year 12 Shi'ite police cadets and 50 Shi'ites praying in a mosque were massacred in the Balochistan capital Quetta. 'Maulana Tariq's death will have long-term implications for the country,' warned Liaquat Baloch, the leader of the right-wing party Jamaat-e-Islami.

Ominously, the outlawed Sipah-e-Sahaba has given the government a three-day 'ultimatum' to arrest Tariq's killers. There is concern that Iranian citizens and property in Pakistan will also be targeted. Tehran is accused of financing a rival Shi'ite group, the Tehrik-e-Jafria, which occasionally hits back by killing Sunni Muslims.

The schism between Shi'ites and Sunnis dates from the time following Prophet Mohammad's death, but nowhere in the world does the hostility cause as much bloodshed as in Pakistan.

General Musharraf banned the Sipah-e-Sahaba in January last year under US pressure, as Tariq, a Taleban ally, was strongly opposed to the American military presence in Afghanistan. But in the National Assembly elections a year ago, radical Islamic leaders were encouraged by the authorities in the hope of containing followers of exiled prime ministers Benazir Bhutto and Nawaz Sharif, who are opposed to General Musharraf.

The Sipah-e-Sahaba has strong support in Punjab partly, analysts say, due to the fact that many large landowners are Shi'ites while the peasants and traders are Sunni.