(For more stories on Afghanistan, click on [ID:AFPAK])
* Bombs in Uruzgan, Kandahar provinces kill 20 civilians
* Over 20 Afghan police, soldiers, guards die in battles
* Five U.S. troops killed by roadside bombs
* Karzai headed for first-round win, fraud could alter result
(Adds American troops killed, gunbattle in Farah, details)
By Hamid Shalizi
KABUL, Sept 12 (Reuters) - Roadside bombs, gunbattles and a suicide strike killed five Americans and dozens of Afghan civilians, troops and police, officials said on Saturday, a bloody day that showed how unrest has spread across the country.
Afghanistan is mired in a drawn-out dispute over election fraud that could test the patience of U.S. President Barack Obama and other Western leaders contemplating whether more troops are needed to defend its government.
Attacks took place in all corners of the country, not only in southern and eastern areas that have long been violent but also in the north and west, which had been comparatively quiet until recent weeks.
Bloodshed has reached its worst level of the eight-year-old war despite record numbers of U.S. and NATO troops.
Election authorities released new, near-complete preliminary results showing incumbent Hamid Karzai headed for a single round victory. That could yet be challenged by a U.N.-backed watchdog that says it has found proof of fraud and has begun voiding ballots from areas where Karzai won overwhelming support.
The latest results gave Karzai 54.3 percent to 28.1 percent for his main opponent, former foreign minister Abdullah Abdullah, with 92.8 percent of polling stations tallied and another 2.15 percent of them set aside due to suspected irregularities. Karzai needs 50 percent of the vote to avoid a second round run-off.
In the worst incident reported on Saturday, the Interior Ministry said a roadside bomb in Uruzgan province in the south had struck two passenger cars, killing 14 civilians.
In Kunduz province in the north, fighters attacked a police post, killing seven policemen including the commander at the checkpoint in a battle that ran from the middle of the night into morning. Two other police were missing, feared captured.
A roadside bomb killed three American service members in the west of the country, and another killed two in the east, a press officer for U.S. and NATO-led troops said.
A roadside bomb in Kandahar province killed six civilians, the Interior Ministry and provincial governor said.
Two suicide bombers struck a detention centre for the National Directorate of Security in the provincial capital, killing a guard and child.
Fighters killed four policemen in an attack on a patrol in Nangarhar province in the east of the country. Six guards from a local security firm were killed when fighters attacked their office in nearby Kunar province.
In Farah province in the West, seven Afghan soldiers died in a lengthy gunbattle with Taliban fighters, and three civilians died when a rocket struck their home, provincial officials said.
INSURGENCY AT STRONGEST
The Taliban insurgency, at its strongest since the militants were ousted by U.S.-backed Afghan forces after the Sept. 11 attacks on the United States in 2001, has spread from its traditional heartland into once-safe northern areas like Kunduz.
NATO-led forces said they had raided compounds in the province overnight, where they "killed a number of militants".
The province has been the scene of escalating fighting over recent months, including a NATO air strike called in by German forces that killed scores of Afghans, including civilians.
The NATO-led force now stands at a record strength of more than 100,000, including about 63,000 Americans, half of whom arrived this year as part of an escalation strategy pursued by Obama.
Obama is expected to decide in coming weeks whether to send more troops, based on a classified assessment of the war by his new commander, General Stanley McChrystal.
Other Western leaders have shown clear signs of frustration with a war that is increasingly unpopular at home.
French President Nicolas Sarkozy, British Prime Minister Gordon Brown and German Chancellor Angela Merkel have jointly proposed a conference this year to set timelines for Afghanistan to take on a bigger role in its own security.
Afghanistan's disputed election could make it more difficult for Obama to seek more troops, by deepening differences between Karzai and the international community.
The day after the U.N.-backed Electoral Complaints Commission announced it had found fraud in the Afghan election, Karzai issued a statement praising it as honest and impartial. (Additional reporting by Mohammad Hamed in KABUL, Ismali Sameem in KANDAHAR, Mohammad Rafiq in JALALABAD and Rohullah Anwari in ASADABAD; writing by Peter Graff)
(For more Reuters coverage of Afghanistan and Pakistan, see: here)