Pakistani politicians were making final preparations on Sunday for a general election the next day that could usher in a parliament intent on forcing US ally President Pervez Musharraf from power.
Authorities imposed a curfew in a northwestern town after 40 were killed in a suicide bomb attack on supporters of assassinated former prime minister Benazir Bhutto on Saturday.
Fears of violence have overshadowed the campaign, which officially ended at midnight on Saturday, especially after opposition leader Bhutto was killed in a gun and bomb attack on December 27 as she left a rally in Rawalpindi.
Voting was postponed from January 8 after Bhutto's assassination, which raised fears about the nuclear-armed country's stability.
Saturday's suicide blast in Parachinar, near the Afghan border, was the most bloody attack in the campaign and looked bound to compound fears of election-day violence that analysts say could hurt turnout.
"The election won't make any difference. There's no chance of any improvement as long as Musharraf is around," said Ahmed Khan, a 33-year-old ethnic Pashtun shopkeeper in the town of Taxila, near Islamabad.
Musharraf's popularity was hurt when he tried to dismiss the country's top judge in March, then took a dive in November when he imposed six weeks of emergency rule to stymie legal challenges to his bid to secure another term as president.
Musharraf is not taking part in the elections for a new parliament and provincial assemblies but his rule looks set to be a decisive factor in the vote.
Other decisive factors, analysts say, will be the strength of a sympathy vote for Bhutto's Pakistan Peoples Party (PPP) and the degree of rigging.
The PPP and the other main opposition party, led by former prime minister Nawaz Sharif, who Musharraf ousted in a 1999 coup, have complained of widespread rigging by Musharraf's allies and they have vowed street protests if they are robbed of victory.
Musharraf, who stepped down as army chief in November, rejects complaints of rigging and says procedures have been refined to prevent cheating.
He said on Saturday he was positive the vote would be fair and peaceful and he hoped for a stable government that would focus on tackling terrorism and economic growth.
Polls open at 8 am (0300 GMT).
Ballots will be counted in the polling stations where they are cast and results are expected to start coming out towards midnight on Monday.
The voting trend in the key battleground province of Punjab, where half of the members of parliament will be elected, should become apparent late on Tuesday morning, with most unofficial results out later in the day.
But with none of the main parties, the PPP, the pro-Musharraf Pakistan Muslim League (PML) and Sharif's Pakistan Muslim League (Nawaz), expected to secure a majority, a coalition between two of the three is likely.
Sharif's party has said it will not enter government so long as Musharraf is president, while the PPP has left options open.
Party leaders were holding final meetings with candidates and planning final news conferences, party officials said.
Nearly 81 million people, about half the population, are registered to vote.
Several hundred foreign observers and thousands of Pakistani observers will be monitoring the vote but they have not been allowed to conduct exit polls.
A European Union monitoring team is expected to announce its preliminary assessment of the vote on Tuesday.