Nine people were killed and several injured when a bomb went off outside an election office of the Pakistan People's Party in Pakistan's northwestern tribal area on the last day of electioneering on Saturday.

The blast occurred outside the election office of PPP candidate Riaz Hussain Shah at a market in Parachinar, the main town of Kurram Agency.

Shah, who was in the office at the time, escaped unhurt, officials said.

Political officials of the area said the bomb was believed to have been hidden in a car parked outside the office. The blast occurred hours before the end of campaigning at midnight for the February 18 general election.

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

Kurram Agency has witnessed fierce sectarian clashes between Shias and Sunnis in the last few months.