UNITED NATIONS (AFP) -- UN chief Ban Ki-moon on Wednesday called on all eligible Afghan voters to cast their ballots in landmark polls to help strengthen Afghanistan's democratic institutions.

“The Secretary General encourages all Afghan women and men eligible to vote to cast their ballots in the upcoming presidential and provincial council elections,” a UN statement said, referring to Thursday's vote.
“By participating in these elections, the Afghan people will help Afghanistan strengthen its democratic institutions, bring fresh vigor to the country's political life, and ultimately reaffirm their commitment to contribute to the peace and prosperity of their nation.”
Ban also urged all candidates, their supporters, as well as domestic and international observers to help “ensure a smooth and successful electoral process.”
In the runup to the landmark elections, the Taliban have stepped up attacks across Afghanistan. At least 21 people were killed on Tuesday and a rocket slammed into the presidential compound in Kabul.
The attacks followed renewed Taliban threats to sabotage Thursday's elections in which 17 million Afghans are eligible to vote.
But the NATO-led coalition said that despite a spike in insurgent strikes, less than one percent of polling stations are at risk of being attacked.
Also on Tuesday, a suicide car bomb targeted a NATO convoy on a busy road near a U.S. military base and a market, killing 10 people including a NATO soldier, and wounding more than 50, officials said.
Ban earlier expressed distress over the death of two UN staffers in the second deadly suicide attack targeting NATO in Kabul in two days.