KABUL (Reuters) – Two Taliban insurgents were killed in a gunbattle in the Afghan capital on Thursday as millions voted in an anxiously awaited presidential election marked by sporadic violence across the country.

The Kabul attack, coming after the Talibansaid 20 of their fighters had infiltrated the capital, was the worst of several on polling stations and voters, mainly in the south and east.

Despite the violence, the United Nations said there were encouraging signs of high turnout.

“The vast majority of polling stations have been able to open and have received voting materials,” said Aleem Siddique, spokesman for the U.N. mission in Kabul.

“…we are seeing queues forming at polling stations in the north, also in the capital, as well as, encouragingly, in the east.”

President Hamid Karzai cast his ballot under tight security at a high school in Kabul, telling reporters he hoped for an outright majority in a single round.

He faces an unexpectedly strong challenge from former foreign minister Abdullah Abdullah, and polls suggest he may not get enough votes to avoid a second round run-off, likely in October. Preliminary results are not expected for at least two weeks.

The election is also a test for U.S. President Barack Obama, who has ordered a massive troop build-up this year as part of a strategy to reverseTaliban gains.

Obama’s envoy for the region, Richard Holbrooke, toured polling stations in Kabul, and said what he’d seen was “open and honest,” adding:” So far every prediction of disaster turned out to be wrong.”

KABUL SHOOTOUT

As he spoke, two Taliban fighters were engaged in a shootout with Afghan forces in the capital. Abdullah Uruzgani, a police battalion commander, told Reuters the two were later killed, while unconfirmed reports said one had blown himself up with a bomb-laden suicide vest and the other had been shot dead.

Attacks have increased in the weeks leading to the poll, with fighters mounting two big suicide car-bomb strikes and a building siege inside the normally secure capital.

Security in most of the country is still better than it was in Iraq when several successful elections were held there, but the Taliban may be able to damage the vote even without big attacks if their threats keep people from the ballot box.

But many Afghans said attacks would not keep them from voting.

“The Afghan people are used to living under the worst circumstances of insecurity and fighting, why should they be afraid to come out and vote?” said Sayed Mustafa, a Kabul student, showing off his ink-stained finger that proved he had voted.