KABUL, Jan 3: Violence marred the start of Afghanistan's New Year with a second US soldier killed in as many days and authorities hunting gunmen who tried to kidnap an elderly American aid worker in Kabul.

The bloodshed served as a reminder of the huge problems still facing US-backed President Hamid Karzai as he struggles to rebuild Afghanistan after 25 devastating years of war.

The American soldier died and three others were wounded in an ambush early on Monday in eastern Afghanistan's Kunar province, a day after another soldier and a suspected Taliban leader were killed in western Herat province.

Two improvised bombs exploded and militants then shot at US troops on a routine patrol in Kunar, near the town of Asadabad, US military spokesman Major Mark McCann told reporters.

McCann added that it was unclear whether the soldier was killed by the blasts or the gunfight, and he was unable to say who carried out the attack. Two US soldiers have now died in Afghanistan since January 1 and the attacks bring the number of US soldiers killed by hostile fire in the country to 60, with 33 US soldiers killed in 2004, compared with just 12 the previous year.

The US-led coalition has more than 18,000 troops in Afghanistan, mostly fighting Taliban and Al Qaeda-linked militants some three years after the hard line regime was toppled from power.

Insurgency-hit Kunar province is also a stronghold of the Hezb-i-Islami militant group led by former Afghan premier Gulbuddin Hekmatyar, who has been declared a wanted terrorist by the United States.

A Turkish engineer working on a road project there was kidnapped and murdered three weeks ago and fears of a wave of Iraq-style hostage-takings have been heightened by the latest kidnap attempt. -AFP