Sectarian violence has flared in the past here between the Shiites, who beat their chests and whip their backs with flails in religious fervour, and the country's majority Sunnis, who oppose the public display of grief.

'Foolproof security arrangements have been completed to maintain law and order during Ashura,' said Mr Tanvir Ashraf Kaira, a minister in Pakistan's largest province, central Punjab.

'Police and other law enforcement agencies have been put on alert and army personnel have been deployed in sensitive districts,' the minister told state media.

'Security has to be enhanced in view of the sensitivity of sects' during the Muslim mourning period of Muharram, which ends with the Ashura ceremonies, he said.

Authorities placed the northwestern town of Hangu under curfew in a bid to avert sectarian violence, two days after a suicide bomber killed seven people in a nearby town, officials said.

They said police commandos would be deployed along routes used by Shiite marchers in North West Frontier Province on the Afghan border, which has been wracked by violence including suicide bombings by Taliban militants.

Shiite Muslims stage religious processions on Ashura to commemorate the death of the Prophet Mohammed's grandson Imam Hussain at Karbala in modern-day Iraq in 680 AD.

Reciting elegies and hymns, participants carry black banners and march behind replicas of Imam Hussain's tomb in Iraq, whipping their backs in a display of devotion.

In the eastern city of Lahore, a major procession was to begin later Wednesday, culminating at a major mosque late Thursday.

A similar procession will begin in Islamabad late Wednesday, joining a big gathering of Shiite mourners in the nearby garrison city of Rawalpindi.

Hussain is also revered by Sunnis, who make up 80 per cent of Pakistan's population of 160 million people, but they oppose the public display of grief.

Clashes between Sunni and Shiite militants in Pakistan have claimed thousands of lives over past decades. -- AFP