KABUL - Four U.S. servicemen were killed by a roadside bomb in Afghanistan on Tuesday, making 2009 the deadliest year for the growing contingent of foreign troops since the overthrow of the Taliban in 2001.

The deaths highlighted the steadily worsening violence in the country, which has been in political limbo since a disputed presidential election last week.

Afghan election authorities were preparing later on Tuesday to publish the first partial results from the presidential election, but the tiny sample may do little to resolve a growing war of words on the outcome.

The election has also been a test of President Barack Obama's strategy of rushing thousands of extra U.S. troops to the country this year in a bid to reverse Taliban gains.

More than 30,000 extra U.S. troops arrived in Afghanistan this year, most part of a package of reinforcements ordered by Obama in May. There are now more than 100,000 Western troops in the country, 63,000 of them Americans.

A NATO statement said the four U.S. service members were killed in the south, the Taliban's heartland, but gave no further details.

That would bring the number of foreign troops who died in Afghanistan this year to 295, according to website icasualties.org, which compiles official figures. Last year was the previous deadliest year when 294 were killed.

The U.S. reinforcements sent by Obama, along with a British contingent already deployed in the south of the country, have advanced deep into formerly Taliban-held territory, taking heavy casualties mainly from roadside bombs. More Western troops have died since March than in the entire period from 2001-2004.

There are fears that a delay in resolving the dispute over the election could stoke further instability.

DISPUTE OVER VOTE RESULT

Late on Monday, Finance Minister Hazrat Omar Zakhilwal said figures supplied to him as a member of the cabinet showed president Hamid Karzai leading with 68 percent of the vote and avoiding a second round.

A spokesman for Karzai's main rival, Abdullah Abdullah, said however that those figures were false. Abdullah has also claimed to be in the lead, and alleges massive fraud on Karzai's behalf.

The ballots were counted immediately after the vote last Thursday and tallies were posted at individual polling stations, but overall totals have not been released to the public while authorities carry out laborious checks.

Election commission spokesman Noor Mohammad Noor said the results of about 10 percent of the vote would be published on Tuesday evening. The overall outcome will not be clear until September 3 when full preliminary results are due, he added.

Karzai's spokesman, Humayun Hamidzada, said the government would be ready to prevent any violence that might result from disputes over the poll.

Afghanistan today has its own entities and will deal with those who break the law and threaten Afghanistan's stability, he said.

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