Eight persons on Sunday succumbed to their injuries raising the toll to 46 in the suicide attack outside the office of the Pakistan People's Party in north-western Pakistan, officials said.

The blast, which took place on Saturday outside the office of a PPP candidate Riaz Hussain Shah at a crowded market in Parachinar, the main town of the troubled Kurram Agency, killed 38 people and injured over 100, heightening security fears for Monday's crucial parliamentary polls.

"Eight more persons have died overnight and the injured are being shifted from Parachinar to Peshawar, the capital of North West Frontier Province," officials said.

According to authorities, the bomber had rammed his explosive-laden vehicle into the office shortly after Shah and his supporters had returned from a rally.

However, Shah had managed to escape unhurt.

Limbs and body parts lay strewn all over the site of the attack, which occurred hours before the end of campaigning for the polls. The dead included six children.

Over 300 people were killed in 2007 in fierce clashes between Shias and Sunnis in Kurram Agency, a tribal area bordering Afghanistan.

The violence ended after a tribal jirga (elders' council) brokered a truce.

PPP chief and former premier Benazir Bhutto [Images] was assassinated in a suicide attack on December 27 and the violence that erupted after her death prompted the Election Commission to postpone the polls by six weeks.

The Pakistan government has deployed nearly 500,000 security personnel, including 81,000 soldiers, to maintain law and order during the polls.